Merge pull request #25 from ModSquadWorkshop/LevelDesign

Level design
Work Done in Class Today
- Various changes made to impress Schrank, such as having the boss spawn minions or
Merge branch 'master' into bullet_effects
Merge pull request #29 from ModSquadWorkshop/bullet_effects

Bullet effects
HealthSystem Observers
work on #11
- Allows objects to register with a HealthSystem to be notified on death.
- Adds LevelManager class which listens for player and boss deaths. Will eventually restart the scene when one dies.
Restart Level
work on #11
- When the player or the boss dies, the game waits for a set amount of time and then restarts.
Cleanup and Performance Fixes
- Removes unused Standard Assets.
- Has bullet shrapnel objects destroy themselves once they are no longer active.
    - We were previously running into performance issues when the level lasted a while because too many old objects were piling up (I guess even idle particle systems are expensive).
More Cleanup
- Woops, forgot to remove a few .meta files.
Bullet Trails
work on #36
- Adds a TrailRenderer to the Bullet prefab which goes a long way towards solving the bullet visibility issue.
Merge pull request #32 from ModSquadWorkshop/basic_boss

Level Restart on Boss or Player Death
Merge commit '10b644c92d1128d73d132d7901c2cc5a8876fd28' into LevelDesign

Conflicts:
	Assets/LevelDesignImport/New Terrain 1.asset