[Xcb] Mixing VSync with XSync

[Jonathan Purol]

I've read through the specification of the functions you send me and I 
believe I now understand how they improve upon my current implementation.

May I ask if you have any idea how widely supported the functions you 
described are? I'm not sure where I could look up such an information 
myself.

Thank you for your time and answers, it's quite hard to find out these 
concepts by myself. Spend hours digging through Qt/GTK's source code 
trying to see how they approach this but found nothing of the sorts.