AssetBundle backgrounds, serialized bgdata, and chart events

[legoandmars]

• Added bgdata as a serialized float[3] array in .tmb files
  • Intended to be used in conjunction with an AssetBundle for events at a specific time/beat
• Added backgroundMovement as a serialized string in .tmb files
  • Preset background movement for both AssetBundle and non-AssetBundle chart backgrounds
  • Current valid values: none, spiral, spiralslower, spiralslowest, bounceslow, bouncefast
• Created the trombackground AssetBundle format for complex chart backgrounds
  • Developed through a Unity project which will be published soon
  • Works very similarly to the base game chart backgrounds, needs a camera/background/foreground
• Added a few helper classes for events
  • TromboneEventManager is used in-editor to hook up objects to chart events
    • Current events include OnBeat, OnBar, NoteStart, NoteEnd, MousePositionUpdated
  • TextEventHandler is used to hook up integer events to Unity text, such as displaying the combo inside of a chart background
  • If AssetBundle backgrounds are not widely adopted, these event classes could serve useful towards developing another format