Drivers may be bad at guessing what is passed to eglGetDisplay, ending
up return non-functioning EGLDisplay's. Using eglGetPlatformDisplay
avoids this issue.
https://bugzilla.gnome.org/show_bug.cgi?id=773629
Lets use a pbuffer surface as a dummy surface instead of a gbm based
one, so that we don't need to rely on the availability of gbm to create
a dummy surface when there is no need for it.
https://bugzilla.gnome.org/show_bug.cgi?id=773629
Add proc symbol loading and helper functions for calling them, dealing
with errors etc. So far no extension symbols are loaded, only the
infrastructure is there.
https://bugzilla.gnome.org/show_bug.cgi?id=773629
