Fixed (SDL2) Pressing Alt+Tab messes up Camera Position after pausing in fullscreen

What happens is that when I pause the game, press Alt+Tab, then go back into the game the camera randomly moves after I unpause.

I can confirm this bug. I think the engine might grab the mouse's movement between being paused and being brought back into focus. Probably just telling the thing to lock the camera for a few milliseconds while resetting the mouse position after unpausing would fix 'er up real good.