Add SDL2 support. SDL 1.2 fallback supported with USE_SDL_1_2 macro.
Start in zoom mode. Small adjustments.
SDL2: Respect fullscreen setting
SDl2: Change Windows SetAppIcon logic. Icon wasn't set when game started in fullscreen
Remove debug_flag and window_flag setting when NDEBUG is not set
Use SDL_MAJOR_VERSION to detect SDL version
Merge branch 'sdl2' of https://github.com/Ghabry/easyrpg-player into sdl2
Silence strict warnings
Check for SDL2 with fallback to SDL1.2
Backport SDL2 debian packages for Travis CI
Use SDL2 with CMake
Omit SDL Surface creation
Always set appicon after creation
Restore to pre-fullscreen resolution when switched back to window instead of 640x480.
Use TARGET_WIDTH/HEIGHT instead of hardcoding. Fix compiler warning.
Merge branch 'sdl2' of https://github.com/fdelapena/easyrpg-player into fdelapena-sdl2

Conflicts:
	src/sdl_ui.cpp
Merge branch 'fdelapena-sdl2' into sdl2