Match visuals for fbconfigs, remove get_dpy_fbc (GH-27)
add isDedicatedSupportingCoreProfiles function

this function should be used to check if the afns driver is supporting core profiles
test implementation of GLX_ARB_create_context

I don't think this should be it at all. But it can be used to create Core profiles where needed. This commit does not claim perfect implementation, just use it at own risk, if you really need this