sdl2: start to write a new window provider based on sdl2. sdl2.pxi has been created from the ignifuga game engine, but maybe functions and definitions are missing. Need to create a generator out of it. At some points, window_sdl (used currently only on iOS) should be removed.)
sdl2: add missing window_sdl2 files, and correctly implement 'auto' fullscreen. read all the missing window event too.
sdl2: add sdl2 image core provider (not complete, need more conversion format, and save support)
sdl2: support for text rendering
sdl2: ignore generated .c
sdl2: fix ignore
sdl2/text: fix color bgra -> rgba
core:sdl2 clipboard provider
Merge branch 'master' into sdl2-support