Game init no longer creates null fields on Players

GameController#init no longer leaves Player.name, Player.army,
Player.largest_army, and Player.longest_road uninitialized.
CollapsableWindow now loses highlight on expand.
Added UiElement framework for window contents.
Translated ControlWindow to the new system.
Moved CardWindow over to new system.
Added testing controls to ControlWindow.
More testing functions.
Fixed bug in mouseover handling code.
Updated PlayersWindow to be a stack of 4 UiPlayerInfo elements.
Pressing Enter in the passcode box on the homepage now starts validation.
Fixed font not loading on homepage (Google Web Font Loader is shit).
Fixed infinite recursion bug in debug overlay drawing.
Cleaned up testing.js, removed some namespace collisions.
Added an overlay information window.