[winswitch] Using Xpra on multi-GPU laptops

[Eric Appleman]

For Xvfb, I couldn't figure out how to get the window to render unless I 
used it with Xpra.

At the very minimum, I think transport would need to cope with 
1920x1080x32 at 60 Hz for vsync. Given this, an XShm solution that is 
similar to hybrid-windump (https://github.com/harp1n/hybrid-windump) 
would probably be needed. The problem is that isn't as complete or 
elegant as Xpra.

For an Optimus notebook, the expectation is very good hardware. CPU will 
be an Intel Arrandale (1st Gen Core i) or Sandy Bridge (2nd Gen Core i) 
and memory should be at least 2GB.

- Eric