Tower Rotations

Towers will now turn in the direction they are shooting. (Except slow
towers)
Towers only show targets during place mode

Still need to show a ghost tower during place.
mattDev Merge

Merged tower rotations from mattDev
Changed currentState to static

Made currentState static so other classes can access it more easily
Final Bug Fixes

Fixed multiple tile effects ending crash.  Fixed sentry tower upgrade.
Fixed game not ending immediately when all enemies are killed
Final Bug Fixes 2

Player starts with $20.  ObjectPools are increased to 64 by default
Merge branch 'davidDev' of https://github.com/Kassanu/TowerDefense into davidDev

Conflicts:
	src/com/eleventhhour/towerdefense/Tower.java