Fixed Issue #288: The Award Screen "Speed Up" Key Bug

This fix creates a very minor issue: the game speed wont be set to its
"Speed Up" state when a player is still holding down the "Speed Up" key
when they have closed the award screen and it has unpaused the game.

They can then resume the "Speed Up" speed state by releasing the "Speed
Up" key and then pressing it again.

I've created a commit which fixes this new issue for ASCII keyboards but it isn't
compatible with other keyboards because it would require OnKeyUp() to be able
to provide UTF-8 key codes in order to identify when the "Speed Up" key has been
released. So I've excluded this commit from this pull request because this commit's
keyboard compatibility problem would prevent the "Speed Up" game speed state
from being disabled. 

If the SDL2 branch will allow OnKeyUp() to provide UTF 8 key codes then I will submit
a pull request to this branch for this excluded commit.