Tobias Himmer
this patch adds a check to the CMake build script to detect whether the VideoCore API is available.
If it is found, it enables SDL_VIDEO_DRIVER_RPI and will also add the needed include/library directory flags to CMAKE_C_FLAGS so the subsequent check for GLES succeeds in picking up the headers.
Seems to work fine on Raspbian.
I added -Wshadow and then turned it off again because of massive variable shadowing in the blit macros.
Feel free to go through that code and fix these if you want. Just uncomment CheckWarnShadow in configure.in if you want to try this.
