Added caching of the window client bounds. Not only does this optimize invocations of the property, but more importantly it helps match behavior with XNA when devices are reset, by ensuring the property doesn't update until the client size changed event is to be invoked.
Moved our graphics device resizing from the RESIZED event to the SIZE_CHANGED event to fix the issues with toggling fullscreen.
Added quick check to the resize method to not do a device reset of the size hasn't actually changed.