Merged Alex Szpakowski's iOS-improvement branch to default.

Fixes Bugzilla #2798.
Fixes Bugzilla #2212.
Fixes Bugzilla #2826.
Fixes Bugzilla #2661.
Fixes Bugzilla #1885.
Fixes Bugzilla #1578.
Fixes Bugzilla #2751.

(whew!)

Notable changes, from Alex's notes:

- The SDL_WINDOW_ALLOW_HIGHDPI flag is now needed (along with SDL_GL_GetDrawableSize or SDL_GetRendererOutputSize) to use Retina / high DPI resolutions, bringing SDL?s Retina-related behavior on iOS in line with Mac OS X. Window dimensions and display modes are now in the ?points? (non-high DPI) coordinate system rather than pixels, whereas SDL_GL_GetDrawableSize is in pixels.

- Reworked the custom extended launch screen code:
	- It now hides after the first SDL_PumpEvents call rather than SDL_CreateWindow, and it fades out in a similar manner to the system launch screen behavior.
	- It now mirrors the system launch screen behavior when deciding which image to display: it falls back to using the Launch Images dictionary in Info.plist if the iOS 8+ launch screen nib isn?t available, and if the Launch Images dictionary doesn?t exist it uses the old standard launch image names.
	- The extended launch screen can now be disabled via the SDL_IPHONE_LAUNCHSCREEN define in SDL_config_iphoneos.h.

- Added support for SDL_HINT_ACCELEROMETER_AS_JOYSTICK.

- Added access to a window view's renderbuffer and framebuffer to syswm.

- Added OpenGL ES debug labels for the Renderbuffer and Framebuffer Objects created with SDL_GL_CreateContext.

- Added support for sRGB OpenGL ES contexts on iOS 7+.

- Updated OpenGL ES contexts to support native-resolution rendering (when SDL_WINDOW_ALLOW_HIGHDPI is enabled) on the iPhone 6 Plus, i.e. 1080x1920 rather than 1242x2208.

- Updated SDL_GL_CreateContext, SDL_GL_SwapWindow, SDL_GL_MakeCurrent, and SDL_GL_DeleteContext to be more robust.

- Updated SDL windows to display a UIView at all times, even when an OpenGL context is not active. This allows rotation, touch events, and other windowing-related events to work properly without an active OpenGL context. It also makes it easier to use SDL_GetWindowWMInfo after creating a SDL window.

- Updated the iOS-specific Objective-C code to use cleaner and more modern language features and APIs, including ARC instead of manual reference counting.

- Updated SDL_HINT_ORIENTATIONS to allow disabling custom orientations if the hint is set with no valid orientation names.

- Fixed several rotation and orientation bugs with windows and display modes, especially in iOS 8+.

- Fixed SDL_SetWindowFullscreen failing to update the status bar visibility on iOS 7+.

- Fixed the orientation of the offset applied to the window?s view when the onscreen keyboard is shown in iOS 8+.

- Fixed SDL_IsScreenKeyboardShown (patch by Phil Hassey.)

- Fixed several major memory leaks caused by missing autorelease pool blocks in the iOS-specific Objective-C code.

- Removed several dead code paths.

- The iOS 7 SDK (Xcode 5) or newer is now required to build SDL for iOS.

android-project/src/org/libsdl/app/SDLActivity.java

@@ -1536,7 +1536,7 @@ class SDLGenericMotionListener_API12 implements View.OnGenericMotionListener {
 
             case InputDevice.SOURCE_MOUSE:
                 action = event.getActionMasked();
-                switch(event.getActionMasked()) {
+                switch (action) {
                     case MotionEvent.ACTION_SCROLL:
                         x = event.getAxisValue(MotionEvent.AXIS_HSCROLL, 0);
                         y = event.getAxisValue(MotionEvent.AXIS_VSCROLL, 0);

src/video/android/SDL_androidtouch.c

@@ -108,8 +108,8 @@ void Android_OnTouch(int touch_device_id_in, int pointer_finger_id_in, int actio
     switch (action) {
         case ACTION_DOWN:
             /* Primary pointer down */
-            Android_GetWindowCoordinates(x, y, &window_x, &window_y);
             if (!separate_mouse_and_touch) {
+                Android_GetWindowCoordinates(x, y, &window_x, &window_y);
                 /* send moved event */
                 SDL_SendMouseMotion(Android_Window, SDL_TOUCH_MOUSEID, 0, window_x, window_y);
                 /* send mouse down event */
@@ -123,8 +123,8 @@ void Android_OnTouch(int touch_device_id_in, int pointer_finger_id_in, int actio
 
         case ACTION_MOVE:
             if (!pointerFingerID) {
-                Android_GetWindowCoordinates(x, y, &window_x, &window_y);
                 if (!separate_mouse_and_touch) {
+                    Android_GetWindowCoordinates(x, y, &window_x, &window_y);
                     /* send moved event */
                     SDL_SendMouseMotion(Android_Window, SDL_TOUCH_MOUSEID, 0, window_x, window_y);
                 }
@@ -136,9 +136,9 @@ void Android_OnTouch(int touch_device_id_in, int pointer_finger_id_in, int actio
             /* Primary pointer up */
             if (!separate_mouse_and_touch) {
                 /* send mouse up */
-                pointerFingerID = (SDL_FingerID) 0;
                 SDL_SendMouseButton(Android_Window, SDL_TOUCH_MOUSEID, SDL_RELEASED, SDL_BUTTON_LEFT);
             }
+            pointerFingerID = (SDL_FingerID) 0;
         case ACTION_POINTER_UP:
             /* Non primary pointer up */
             SDL_SendTouch(touchDeviceId, fingerId, SDL_FALSE, x, y, p);

src/video/wayland/SDL_waylandvideo.c

@@ -277,21 +277,19 @@ Wayland_VideoInit(_THIS)
 {
     SDL_VideoData *data = SDL_malloc(sizeof *data);
     if (data == NULL)
-        return 0;
+        return SDL_OutOfMemory();
     memset(data, 0, sizeof *data);
 
     _this->driverdata = data;
 
     data->display = WAYLAND_wl_display_connect(NULL);
     if (data->display == NULL) {
-        SDL_SetError("Failed to connect to a Wayland display");
-        return 0;
+        return SDL_SetError("Failed to connect to a Wayland display");
     }
 
     data->registry = wl_display_get_registry(data->display);
     if (data->registry == NULL) {
-        SDL_SetError("Failed to get the Wayland registry");
-        return 0;
+        return SDL_SetError("Failed to get the Wayland registry");
     }
 
     wl_registry_add_listener(data->registry, &registry_listener, data);
@@ -304,8 +302,7 @@ Wayland_VideoInit(_THIS)
 
     data->xkb_context = WAYLAND_xkb_context_new(0);
     if (!data->xkb_context) {
-        SDL_SetError("Failed to create XKB context");
-        return 0;
+        return SDL_SetError("Failed to create XKB context");
     }
 
     Wayland_InitMouse();

src/video/wayland/SDL_waylandwindow.c

@@ -147,7 +147,7 @@ int Wayland_CreateWindow(_THIS, SDL_Window *window)
 
     data = calloc(1, sizeof *data);
     if (data == NULL)
-        return 0;
+        return SDL_OutOfMemory();
 
     c = _this->driverdata;
     window->driverdata = data;