Added Abstract Obstacle

Added abstract obstacle class
Added basic obstacles

Added moss graphics and basic behaviour
Added lava graphics and basic behaviour
Added spikes graphics and basic behaviour
Slightly Modified Obstacles

Simplified constructors
Merge remote-tracking branch 'origin/Obstacles'

Conflicts:
	TombRacer/bin/TombRacer.swf
Merge branch 'master' of https://github.com/theKristi/GameDev_spring14