GtkGLArea : Wayland support

Hi, 

I just submitted a bug & a patch to implement Wayland support in GtkGLarea : 

https://bugzilla.gnome.org/show_bug.cgi?id=729290 

It basically allows to run GtkGLArea programs under Wayland, create a 
widget, and render through Open GLES in this widget. 

There is only one example now ("simple_wl") which renders a triangle with 
GLESv1_CM :
http://www.tarnyko.net/repo/gtkglarea-wayland.png 

It will build additionally or alone, depending on the libs you have. I have 
a hard require on GLESv1 due to that, sorry, will fix that later. 

Regards,
Tarnyko