Fix warnings about unused variables [-Wunused-variable]

Fixes the following GCC 5 warnings:
```
drivers/gles2/rasterizer_scene_gles2.cpp:1139:15: warning: unused variable 'offset' [-Wunused-variable]
drivers/gles2/rasterizer_scene_gles2.cpp:1205:39: warning: unused variable 'multi_mesh' [-Wunused-variable]
drivers/gles2/rasterizer_storage_gles2.cpp:359:7: warning: unused variable 'srgb' [-Wunused-variable]
drivers/gles2/shader_gles2.cpp:1016:45: warning: unused variable 'texture_hints' [-Wunused-variable]
editor/animation_track_editor.cpp:776:9: warning: unused variable 'keys_to' [-Wunused-variable]
editor/editor_inspector.cpp:273:7: warning: unused variable 'vs_height' [-Wunused-variable]
editor/editor_themes.cpp:202:10: warning: unused variable 'begin_time' [-Wunused-variable]
editor/editor_themes.cpp:239:10: warning: unused variable 'end_time' [-Wunused-variable]
editor/plugins/animation_blend_tree_editor_plugin.cpp:726:17: warning: unused variable 'an' [-Wunused-variable]
editor/plugins/script_text_editor.cpp:1278:8: warning: unused variable 'fold_state' [-Wunused-variable]
main/main.cpp:132:13: warning: 'use_vsync' defined but not used [-Wunused-variable]
modules/cvtt/image_compress_cvtt.cpp:231:8: warning: unused variable 'y_end' [-Wunused-variable]
modules/cvtt/image_compress_cvtt.cpp:311:6: warning: unused variable 'shift' [-Wunused-variable]
modules/gdscript/gdscript_editor.cpp:58:7: warning: unused variable 'th' [-Wunused-variable]
modules/gridmap/grid_map.cpp:1084:6: warning: unused variable 'ofs' [-Wunused-variable]
modules/theora/video_stream_theora.cpp:442:9: warning: unused variable 'tr' [-Wunused-variable]
modules/visual_script/visual_script_editor.cpp:2606:6: warning: unused variable 'count' [-Wunused-variable]
modules/visual_script/visual_script_editor.cpp:2829:6: warning: unused variable 'seq_count' [-Wunused-variable]
modules/visual_script/visual_script_editor.cpp:2844:24: warning: unused variable 'vnode_function' [-Wunused-variable]
modules/websocket/lws_peer.cpp:122:12: warning: unused variable 'peer_data' [-Wunused-variable]
modules/websocket/lws_peer.cpp:135:12: warning: unused variable 'peer_data' [-Wunused-variable]
modules/websocket/lws_peer.cpp:63:12: warning: unused variable 'peer_data' [-Wunused-variable]
modules/websocket/lws_peer.cpp:91:12: warning: unused variable 'peer_data' [-Wunused-variable]
platform/android/export/export.cpp:763:16: warning: unused variable 'node_size' [-Wunused-variable]
scene/gui/rich_text_label.cpp:850:10: warning: unused variable 'x_ofs' [-Wunused-variable]
scene/gui/text_edit.cpp:653:8: warning: unused variable 'tab_w' [-Wunused-variable]
scene/resources/bit_mask.cpp:186:6: warning: unused variable 'i' [-Wunused-variable]
scene/resources/mesh.cpp:549:20: warning: '_array_name' defined but not used [-Wunused-variable]
servers/audio/audio_rb_resampler.cpp:107:10: warning: unused variable 'v2' [-Wunused-variable]
servers/audio/audio_rb_resampler.cpp:108:10: warning: unused variable 'v3' [-Wunused-variable]
servers/audio/audio_rb_resampler.cpp:109:10: warning: unused variable 'v4' [-Wunused-variable]
servers/audio/audio_rb_resampler.cpp:110:10: warning: unused variable 'v5' [-Wunused-variable]
servers/audio/audio_rb_resampler.cpp:111:10: warning: unused variable 'v0n' [-Wunused-variable]
servers/audio/audio_rb_resampler.cpp:112:10: warning: unused variable 'v1n' [-Wunused-variable]
servers/audio/audio_rb_resampler.cpp:113:10: warning: unused variable 'v2n' [-Wunused-variable]
servers/audio/audio_rb_resampler.cpp:114:10: warning: unused variable 'v3n' [-Wunused-variable]
servers/audio/audio_rb_resampler.cpp:115:10: warning: unused variable 'v4n' [-Wunused-variable]
servers/audio/audio_rb_resampler.cpp:116:10: warning: unused variable 'v5n' [-Wunused-variable]
servers/visual/default_mouse_cursor.xpm:2:21: warning: 'default_mouse_cursor_xpm' defined but not used [-Wunused-variable]
```

6 files changed, 11 insertions, 45 deletions

diff --git a/modules/cvtt/image_compress_cvtt.cpp b/modules/cvtt/image_compress_cvtt.cpp
index 425d8db183..732b9cf733 100644
--- a/modules/cvtt/image_compress_cvtt.cpp
+++ b/modules/cvtt/image_compress_cvtt.cpp
@@ -228,8 +228,6 @@ void image_compress_cvtt(Image *p_image, float p_lossy_quality, Image::CompressS
 		uint8_t *out_bytes = &wb[dst_ofs];
 
 		for (int y_start = 0; y_start < h; y_start += 4) {
-			int y_end = y_start + 4;
-
 			CVTTCompressionRowTask row_task;
 			row_task.width = w;
 			row_task.height = h;
@@ -308,7 +306,6 @@ void image_decompress_cvtt(Image *p_image) {
 	int target_size = Image::get_image_data_size(w, h, target_format, p_image->has_mipmaps());
 	int mm_count = p_image->get_mipmap_count();
 	data.resize(target_size);
-	int shift = Image::get_format_pixel_rshift(target_format);
 
 	PoolVector<uint8_t>::Write wb = data.write();
 
diff --git a/modules/gdscript/gdscript_editor.cpp b/modules/gdscript/gdscript_editor.cpp
index a9b641de50..3194f19aa9 100644
--- a/modules/gdscript/gdscript_editor.cpp
+++ b/modules/gdscript/gdscript_editor.cpp
@@ -33,12 +33,9 @@
 #include "core/engine.h"
 #include "core/global_constants.h"
 #include "core/os/file_access.h"
-#include "editor/editor_settings.h"
 #include "gdscript_compiler.h"
 
 #ifdef TOOLS_ENABLED
-#include "core/engine.h"
-#include "core/reference.h"
 #include "editor/editor_file_system.h"
 #include "editor/editor_settings.h"
 #endif
diff --git a/modules/gridmap/grid_map.cpp b/modules/gridmap/grid_map.cpp
index a480c4183e..a8fdf8cf1f 100644
--- a/modules/gridmap/grid_map.cpp
+++ b/modules/gridmap/grid_map.cpp
@@ -29,37 +29,19 @@
 /*************************************************************************/
 
 #include "grid_map.h"
-#include "core/message_queue.h"
-#include "scene/3d/light.h"
-#include "scene/resources/surface_tool.h"
-#include "servers/visual_server.h"
 
 #include "core/io/marshalls.h"
-#include "core/os/os.h"
+#include "core/message_queue.h"
+#include "scene/3d/light.h"
 #include "scene/resources/mesh_library.h"
+#include "scene/resources/surface_tool.h"
 #include "scene/scene_string_names.h"
+#include "servers/visual_server.h"
 
 bool GridMap::_set(const StringName &p_name, const Variant &p_value) {
 
 	String name = p_name;
 
-	/*	} else if (name=="cells") {
-		PoolVector<int> cells = p_value;
-		int amount=cells.size();
-		PoolVector<int>::Read r = cells.read();
-		ERR_FAIL_COND_V(amount&1,false); // not even
-		cell_map.clear();
-		for(int i=0;i<amount/3;i++) {
-
-
-			IndexKey ik;
-			ik.key=decode_uint64(&r[i*3]);
-			Cell cell;
-			cell.cell=uint32_t(r[i*+1]);
-			cell_map[ik]=cell;
-
-		}
-		_recreate_octant_data();*/
 	if (name == "data") {
 
 		Dictionary d = p_value;
@@ -80,7 +62,9 @@ bool GridMap::_set(const StringName &p_name, const Variant &p_value) {
 				cell_map[ik] = cell;
 			}
 		}
+
 		_recreate_octant_data();
+
 	} else if (name == "baked_meshes") {
 
 		clear_baked_meshes();
@@ -103,8 +87,9 @@ bool GridMap::_set(const StringName &p_name, const Variant &p_value) {
 
 		_recreate_octant_data();
 
-	} else
+	} else {
 		return false;
+	}
 
 	return true;
 }
@@ -1081,8 +1066,6 @@ void GridMap::make_baked_meshes(bool p_gen_lightmap_uv, float p_lightmap_uv_texe
 		}
 	}
 
-	int ofs = 0;
-
 	for (Map<OctantKey, Map<Ref<Material>, Ref<SurfaceTool> > >::Element *E = surface_map.front(); E; E = E->next()) {
 
 		Ref<ArrayMesh> mesh;
diff --git a/modules/theora/video_stream_theora.cpp b/modules/theora/video_stream_theora.cpp
index d9677b505c..d72d74cf79 100644
--- a/modules/theora/video_stream_theora.cpp
+++ b/modules/theora/video_stream_theora.cpp
@@ -439,7 +439,7 @@ void VideoStreamPlaybackTheora::update(float p_delta) {
 					}
 				}
 
-				int tr = vorbis_synthesis_read(&vd, ret - to_read);
+				vorbis_synthesis_read(&vd, ret - to_read);
 
 				audio_frames_wrote += ret - to_read;
 
diff --git a/modules/visual_script/visual_script_editor.cpp b/modules/visual_script/visual_script_editor.cpp
index 4736556d6a..f4e7d9831a 100644
--- a/modules/visual_script/visual_script_editor.cpp
+++ b/modules/visual_script/visual_script_editor.cpp
@@ -2603,7 +2603,6 @@ void VisualScriptEditor::connect_data(Ref<VisualScriptNode> vnode_old, Ref<Visua
 	if (port >= value_count) {
 		port = 0;
 	}
-	int count = vnode_old->get_output_value_port_count() + vnode_old->get_output_sequence_port_count();
 	undo_redo->add_do_method(script.ptr(), "data_connect", edited_func, port_action_node, port, new_id, 0);
 	undo_redo->add_undo_method(script.ptr(), "data_disconnect", edited_func, port_action_node, port, new_id, 0);
 	undo_redo->commit_action();
@@ -2826,7 +2825,6 @@ void VisualScriptEditor::_selected_connect_node(const String &p_text, const Stri
 }
 
 void VisualScriptEditor::connect_seq(Ref<VisualScriptNode> vnode_old, Ref<VisualScriptNode> vnode_new, int new_id) {
-	int seq_count = vnode_old->get_output_sequence_port_count();
 	VisualScriptOperator *vnode_operator = Object::cast_to<VisualScriptOperator>(vnode_new.ptr());
 	if (vnode_operator != NULL && vnode_operator->has_input_sequence_port() == false) {
 		return;
@@ -2841,7 +2839,7 @@ void VisualScriptEditor::connect_seq(Ref<VisualScriptNode> vnode_old, Ref<Visual
 	if (vnode_new->has_input_sequence_port() == false) {
 		return;
 	}
-	VisualScriptFunction *vnode_function = Object::cast_to<VisualScriptFunction>(vnode_old.ptr());
+
 	undo_redo->create_action(TTR("Connect Node Sequence"));
 	int pass_port = -vnode_old->get_output_sequence_port_count() + 1;
 	int return_port = port_action_output - 1;
@@ -3367,11 +3365,6 @@ void VisualScriptEditor::_member_option(int p_option) {
 					undo_redo->add_undo_method(script.ptr(), "data_connect", name, E->get().from_node, E->get().from_port, E->get().to_node, E->get().to_port);
 				}
 
-				/*
-				for(int i=0;i<script->function_get_argument_count(name);i++) {
-					undo_redo->add_undo_method(script.ptr(),"function_add_argument",name,script->function_get_argument_name(name,i),script->function_get_argument_type(name,i));
-				}
-				*/
 				undo_redo->add_do_method(this, "_update_members");
 				undo_redo->add_undo_method(this, "_update_members");
 				undo_redo->add_do_method(this, "_update_graph");
diff --git a/modules/websocket/lws_peer.cpp b/modules/websocket/lws_peer.cpp
index 245b28b608..2f022bcfc9 100644
--- a/modules/websocket/lws_peer.cpp
+++ b/modules/websocket/lws_peer.cpp
@@ -30,6 +30,7 @@
 #ifndef JAVASCRIPT_ENABLED
 
 #include "lws_peer.h"
+
 #include "core/io/ip.h"
 
 // Needed for socket_helpers on Android at least. UNIXes has it, just include if not windows
@@ -60,7 +61,6 @@ Error LWSPeer::read_wsi(void *in, size_t len) {
 
 	ERR_FAIL_COND_V(!is_connected_to_host(), FAILED);
 
-	PeerData *peer_data = (PeerData *)(lws_wsi_user(wsi));
 	uint32_t size = in_size;
 	uint8_t is_string = lws_frame_is_binary(wsi) ? 0 : 1;
 
@@ -88,7 +88,6 @@ Error LWSPeer::write_wsi() {
 
 	ERR_FAIL_COND_V(!is_connected_to_host(), FAILED);
 
-	PeerData *peer_data = (PeerData *)(lws_wsi_user(wsi));
 	PoolVector<uint8_t> tmp;
 	int left = rbw.data_left();
 	uint32_t to_write = 0;
@@ -119,7 +118,6 @@ Error LWSPeer::put_packet(const uint8_t *p_buffer, int p_buffer_size) {
 
 	ERR_FAIL_COND_V(!is_connected_to_host(), FAILED);
 
-	PeerData *peer_data = (PeerData *)lws_wsi_user(wsi);
 	rbw.write((uint8_t *)&p_buffer_size, 4);
 	rbw.write(p_buffer, MIN(p_buffer_size, rbw.space_left()));
 	out_count++;
@@ -132,8 +130,6 @@ Error LWSPeer::get_packet(const uint8_t **r_buffer, int &r_buffer_size) {
 
 	ERR_FAIL_COND_V(!is_connected_to_host(), FAILED);
 
-	PeerData *peer_data = (PeerData *)lws_wsi_user(wsi);
-
 	if (in_count == 0)
 		return ERR_UNAVAILABLE;