Implement BattleObject class
Add DROID_SIZE and DROID_SPEED
Change default value when unable to calculate avg LPS
Implement Droid class with basic movement
Add NAV_DELAY
Add battleMap and lastHeadingTime attribs
Add isValid() and stub for isClear()
Implement basic movement
Add basic collision detection
Move faction attrib into BattleObject base class
Change renderBattleObject() to draw square instead of circle symbol
Add Factory class
Merge branch 'feature/battle_objects' into feature/unit_creation

Conflicts:
	Overload/src/com/spillovergames/overload/BattleObject.java
	Overload/src/com/spillovergames/overload/BattleView.java
	Overload/src/com/spillovergames/overload/Defaults.java
	Overload/src/com/spillovergames/overload/Droid.java
Remove debug logging
Add addObject()
Refine buildUnit()
Enable player on-demand unit creation
Fix unit size to use radial size consistently
Add color to unit symbols
Centralize map logic into BattleMap class