Updating SideScrollController to rotate toward z=0 path as it strays off of it, also improving enemy controller to only move on z=0. Adding free assets from the Unity Asset Store.
Refactoring JetPackParticleController and SideScrollController for easy implementation of pickup system integration later. Added a turret model and some other assets.
Adding turret prefab and cleaning up directory.
Merge pull request #22 from CoryG89/master

Adding turret prefab and cleaning up Solobot directory.