Style: Set clang-format Standard to Cpp11

For us, it practically only changes the fact that `A<A<int>>` is now
used instead of the C++03 compatible `A<A<int> >`.

Note: clang-format 10+ changed the `Standard` arguments to fully
specified `c++11`, `c++14`, etc. versions, but we can't use `c++17`
now if we want to preserve compatibility with clang-format 8 and 9.
`Cpp11` is still supported as deprecated alias for `Latest`.

.clang-format

@@ -112,11 +112,11 @@ UseTab:          Always
 ---
 ### C++ specific config ###
 Language:        Cpp
-Standard:        Cpp03
+Standard:        Cpp11
 ---
 ### ObjC specific config ###
 Language:        ObjC
-Standard:        Cpp03
+Standard:        Cpp11
 ObjCBlockIndentWidth: 4
 # ObjCSpaceAfterProperty: false
 # ObjCSpaceBeforeProtocolList: true

doc/classes/TreeItem.xml

@@ -23,8 +23,7 @@
 			<argument index="4" name="tooltip" type="String" default="&quot;&quot;">
 			</argument>
 			<description>
-				Adds a button with [Texture2D] [code]button[/code] at column [code]column[/code]. The [code]button_idx[/code] index is used to identify the button when calling other methods. If not specified, the next available index is used, which may be retrieved by calling [method get_button_count] immediately after this method. Optionally, the button can be [code]disabled[/code] and have a [code]tooltip
-				[/code].
+				Adds a button with [Texture2D] [code]button[/code] at column [code]column[/code]. The [code]button_idx[/code] index is used to identify the button when calling other methods. If not specified, the next available index is used, which may be retrieved by calling [method get_button_count] immediately after this method. Optionally, the button can be [code]disabled[/code] and have a [code]tooltip[/code].
 			</description>
 		</method>
 		<method name="call_recursive" qualifiers="vararg">

platform/iphone/app_delegate.h

@@ -36,9 +36,11 @@
 
 #import <CoreMotion/CoreMotion.h>
 
-#if defined(OPENGL_ENABLED)
-@interface AppDelegate : NSObject <UIApplicationDelegate, GLViewDelegate> {
-#endif
+// FIXME: Add support for both GLES2 and Vulkan when GLES2 is implemented again,
+// so it can't be done with compilation time branching.
+//#if defined(OPENGL_ENABLED)
+//@interface AppDelegate : NSObject <UIApplicationDelegate, GLViewDelegate> {
+//#endif
 #if defined(VULKAN_ENABLED)
 @interface AppDelegate : NSObject <UIApplicationDelegate> {
 #endif

platform/iphone/app_delegate.mm

@@ -648,7 +648,6 @@ static int frame_count = 0;
 	view_controller = [[ViewController alloc] init];
 	view_controller.view = glView;
 
-
 	_set_keep_screen_on(bool(GLOBAL_DEF("display/window/energy_saving/keep_screen_on", true)) ? YES : NO);
 	glView.useCADisplayLink =
 			bool(GLOBAL_DEF("display.iOS/use_cadisplaylink", true)) ? YES : NO;