Super Cool Update

-Changed the min and max of MWindow Size to prevent absurd resizing.

-Fixed a potential bug by replacing a literal with a cons variable.

-The card transfer method now works better. It finds a near pile and
stacks there or comes back to where it came from.

-Implemented a method() to calculate distances center to center.

-A new attribute <center> was added to CardPile and CardLabel.

-Fixed a disastrous bug that made the bottom card of a pile to NEVER
show up.

-Wrote the header of a method to validate moves.