Memory Door and background music

Got the memory stuff in there along with the overworld background music
-Deleting some unneeded stuff from the repo before we begin merging everything
-Updated .gitignore to no longer accept .suo files
Merge branch 'james-dev' into dev

Conflicts:
	PossessionGame/Assets/Scenes/OverWorldBeta.unity
-Overhauled the Audio Manager script. It is now a singleton and shows up in every scene once called.
-Keys now only appear above the door once the door has been beaten
-A bunch of other changes and fixes
-Also deleted a bunch of files that aren't needed anymore