Add ArcherTower defense
Modify Structure and Defense framework to accomodate Enemies
Modify to identify shooting Entity
Merge branch 'structures'

Conflicts:
	src/Fireblast.java
	src/Structure.java
Fix mouse listener for projectile shooting
Abstractify projectiles
Lower speed of player and projectiles.
Increase window size
Clarify x vs gridX
Merge branch 'grid'

Conflicts:
	src/Barrage.java
	src/Defense.java
	src/Structure.java
Update Defense and Enemy. Add QuakeTower defense.
Merge branch 'spells'

Conflicts:
	src/GamePanel.java
Merge branch 'structures'

Conflicts:
	src/Defense.java