Fixed NUllPointerException
Fixed circle around tower disappearing after the next frame.
Projectiles can no longer hit zombie into a wall
Projectiles will also not move a zombie if it has not spawned completely.
Fixed bug where clients would think the round never ended
Added sprite and main class for HealthPack
Integrated HealthPack into the game
Players can now pickup HealthPacks and it will increase their health.
Fixed bug when clients couldn't drop HealthPacks.
Zombies speed increases and their spawn delay decreases as round number increases.
This file should have never been tracked.
Added a SteelBarrier Building.
It has more health, costs more than a Barrier.
Added a boss zombie that comes every 10 rounds
Forgot to add the BossZombie class file
Added the FreezeTower building.

The building does not freeze zombies yet.
Centered the the buildings radius around it's center.
FreezeTower now slows down zombies that come in range.
Merge branch 'freezeTower'

FreezeTower is finished.
Radius is now centered when placing ArsenalItems.
Fixed bug where buildings werent getting destroyed when health was zero.
Changed radius color to purple.