MouseState.Button out of date

MonoGame stops processing mouse events when the game is not active, leading to the mouse buttons being 'out of date' when the game window becomes active again. 

Fix is to reset to current actual state on window activate.
So this is bugged...  not sure why I thought this was a good idea.

This ends up sending a fake mouse event with an incorrect mouse position thru to the game.  So click on the title bar to activate the game window, the position that is relative to the Window title bar area and not relative to the client area is passed thru.

Why is this a good thing?