Alice Chess implementation in progress

Still needs to support two boards and all UI-related things. Not sure if
logic is correct or not.
AliceChess listeners now working

MouseListeners now working; still need to allow for both boards to be
displayed and used.
Moved undo capability completely to subclassed Games, fixed bug when undoing during animation
Code organization to prepare for double boards
Added ability to switch view between boards in Alice
Fixed some bugs in Alice variant

Fixed bug that prevented player 2 from seeing highlighted squares.
Removed hardcode to be able to test game.

Game has problems when moving pieces on second board.
Finished fixing bugs, en passant

Finished fixing (hopefully) the last bug from generalizing previous
hard-coding. Also implemented en passant.

General gameplay for PvP should be working, but testing needed.
Implemented Undo

Implemented Undo feature, along with some brushing up of FEN stuff.
Made fading animation for Alice
Fixed Alice bugs

Now king isn't allowed to move into check, and when in check, you must
remove it properly. Needs some more testing, but will probably merge
back into main branch.
Merge pull request #3 from william1lai/in-progress

In progress