Store the resolutions detected by SDL in a cvar. The mod code can
then optionally use the cvar to offer a better choice in the menu.
Signed-off-by: Ludwig Nussel <ludwig.nussel@suse.de>
make the Makefile check sufficiently portable
* Remove unnecessary GL PFN... casts from SDL_GL_GetProcAddress calls
* Replace OS X uname workaround with Solaris workaround, as I believe OS X
uname now behaves the same as GNU name
* Revert to using literal function pointers for GL extensions rather than PFN*
typedefs as some platforms' headers are broken enough that they prevent
SDL_opengl.h from fixing things up if the PFN* typedefs are missing