Dmitry Marakasov
Unlike SDL_Rect (typedef struct SDL_Rect {} SDL_Rect), SDL_Point (typedef struct {} SDL_Point) structure is unnamed. This feels inconsistent and makes it impossible to use forward declaration for SDL_Point, having to include whole SDL_rect.h instead.
If the app is in landscape mode and the user presses the power button, a pause
is followed immediately by a surfaceChanged event because the lock screen
is shown in portrait mode. This triggers a "false" resume.
So, we just pause and resume following the onWindowFocusChanged events.
Also, wait for SDL_APP_WILLENTERBACKGROUND and SDL_APP_DIDENTERBACKGROUND before
blocking the event pump.
