Final merging

Accidentally didn't make sure that everything compiled and worked after
that recent push.
Small Changes

Added 'M' press to switch between melee/range.  'J' to attack, 'K' to
switch attack styles when in melee.  Range has ridiculous fire speed.
Fixed bug with attacking (how long wait was to new attack).
Characters stop moving when they hit objects
Small formatting changes

Bigger stuff to come tonight
Fixed a bug with movement

Oops, I added a bug with movement, but I fixed it. See the changes to
PlayableCharacter.java. Also, I added an empty constructor to Coordinate
because I didn't want to have to specify values for x and y at
construction.
Added prototype map, fixed moving diagonal bug
Pressing Enter at start menu starts the game

Ideally, I would like to have more keyboard functionality in the start
menus (i.e. being able to scroll through buttons with the arrow keys and
pressing Enter to select a menu option). But this is not really a
priority right now.
Added warp functionality, moved Map to another package

Added the "prototype_map", which is a modified version of the Link to
the Past map. Also added an arrow image and made the attack controls a
little more responsive (especially switching weapons).
Added a StandStillAI movement class