Fix warnings for operator precedence disambiguation [-Wparentheses]

Fixes the following GCC 5 warnings:
```
core/io/resource_format_binary.cpp:1721:29: warning: suggest parentheses around arithmetic in operand of '|' [-Wparentheses]
core/typedefs.h:108:24: warning: suggest parentheses around comparison in operand of '!=' [-Wparentheses]
editor/plugins/spatial_editor_plugin.cpp:2202:58: warning: suggest parentheses around comparison in operand of '!=' [-Wparentheses]
editor/plugins/spatial_editor_plugin.cpp:5002:12: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
main/input_default.cpp:346:59: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
main/input_default.cpp:348:60: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
main/input_default.cpp:579:57: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
modules/gridmap/grid_map_editor_plugin.cpp:613:14: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
modules/theora/video_stream_theora.cpp:335:34: warning: suggest parentheses around '+' in operand of '&' [-Wparentheses]
modules/theora/video_stream_theora.cpp:336:35: warning: suggest parentheses around '+' in operand of '&' [-Wparentheses]
modules/visual_script/visual_script_property_selector.cpp:215:38: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
scene/gui/rich_text_label.cpp:424:84: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
scene/gui/rich_text_label.cpp:512:80: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
scene/gui/scroll_container.cpp:173:36: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
scene/gui/scroll_container.cpp:173:86: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
scene/gui/tree.cpp:1419:98: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
```

3 files changed, 5 insertions, 4 deletions

diff --git a/scene/gui/rich_text_label.cpp b/scene/gui/rich_text_label.cpp
index 81f1ee67c5..d8c312397d 100644
--- a/scene/gui/rich_text_label.cpp
+++ b/scene/gui/rich_text_label.cpp
@@ -421,7 +421,7 @@ int RichTextLabel::_process_line(ItemFrame *p_frame, const Vector2 &p_ofs, int &
 
 								int cw = 0;
 
-								bool visible = visible_characters < 0 || p_char_count < visible_characters && YRANGE_VISIBLE(y + lh - line_descent - line_ascent, line_ascent + line_descent);
+								bool visible = visible_characters < 0 || (p_char_count < visible_characters && YRANGE_VISIBLE(y + lh - line_descent - line_ascent, line_ascent + line_descent));
 								if (visible)
 									line_is_blank = false;
 
@@ -509,7 +509,7 @@ int RichTextLabel::_process_line(ItemFrame *p_frame, const Vector2 &p_ofs, int &
 
 				ENSURE_WIDTH(img->image->get_width());
 
-				bool visible = visible_characters < 0 || p_char_count < visible_characters && YRANGE_VISIBLE(y + lh - font->get_descent() - img->image->get_height(), img->image->get_height());
+				bool visible = visible_characters < 0 || (p_char_count < visible_characters && YRANGE_VISIBLE(y + lh - font->get_descent() - img->image->get_height(), img->image->get_height()));
 				if (visible)
 					line_is_blank = false;
 
diff --git a/scene/gui/scroll_container.cpp b/scene/gui/scroll_container.cpp
index e3fb602065..26da16569a 100644
--- a/scene/gui/scroll_container.cpp
+++ b/scene/gui/scroll_container.cpp
@@ -30,6 +30,7 @@
 
 #include "scroll_container.h"
 #include "core/os/os.h"
+
 bool ScrollContainer::clips_input() const {
 
 	return true;
@@ -170,7 +171,7 @@ void ScrollContainer::_gui_input(const Ref<InputEvent> &p_gui_input) {
 			Vector2 motion = Vector2(mm->get_relative().x, mm->get_relative().y);
 			drag_accum -= motion;
 
-			if (beyond_deadzone || scroll_h && Math::abs(drag_accum.x) > deadzone || scroll_v && Math::abs(drag_accum.y) > deadzone) {
+			if (beyond_deadzone || (scroll_h && Math::abs(drag_accum.x) > deadzone) || (scroll_v && Math::abs(drag_accum.y) > deadzone)) {
 				if (!beyond_deadzone) {
 					propagate_notification(NOTIFICATION_SCROLL_BEGIN);
 					emit_signal("scroll_started");
diff --git a/scene/gui/tree.cpp b/scene/gui/tree.cpp
index 23e4c26695..db0cae6eda 100644
--- a/scene/gui/tree.cpp
+++ b/scene/gui/tree.cpp
@@ -1416,7 +1416,7 @@ int Tree::draw_item(const Point2i &p_pos, const Point2 &p_draw_ofs, const Size2
 
 		while (c) {
 
-			if (cache.draw_relationship_lines == 1 && (c->get_parent() != root || c->get_parent() == root && !hide_root)) {
+			if (cache.draw_relationship_lines == 1 && (c->get_parent() != root || !hide_root)) {
 				int root_ofs = children_pos.x + ((p_item->disable_folding || hide_folding) ? cache.hseparation : cache.item_margin);
 				int parent_ofs = p_pos.x + ((p_item->disable_folding || hide_folding) ? cache.hseparation : cache.item_margin);
 				Point2i root_pos = Point2i(root_ofs, children_pos.y + label_h / 2) - cache.offset + p_draw_ofs;