Bugfix mouse follows focus window swapping

Because of async nature of screen reflows, the focusWindow would focus then window before it was moved messing up the mouse follows focus logic.  This fixes that by passing a BOOL whether or not to call focusWindow after reflowing.  Their might be a better way to design how this is implemented but should get the ball rolling on fixing these issues.

Fixes
https://github.com/ianyh/Amethyst/issues/240
https://github.com/ianyh/Amethyst/issues/183