Albert Casals
On a RaspberryPI, it might become convenient to specify the Dispmanx layer SDL uses.
Currently, it is hardcoded to be 10000 to sit above most applications.
This can be specially useful when integrating other graphical apps and frameworks like OMXplayer, QT5 etc.. in order to have more flexibility on their Z-order.
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().
