[rbp] Handle resolution changes during video stream.

When the resolution changes, GPU sends a port settings changed message. Host has to acknowledge it by disabling and enabling the affected ports.

I also call g_renderManager.Configure with the new dimensions.

There's been a couple of test builds with positive reports:
http://forum.xbmc.org/showthread.php?tid=155587&pid=1343585#pid1343585
http://forum.stmlabs.com/showthread.php?tid=6694&pid=57676#pid57676