first draft of the new timeline based animation API
add missing import
optimized some Vector2D instantiation away
typo / nameing fixed
add Looping and play controls (Play, Pause, ..) to Timeline
interface Timeline must extend Updateable
renamed PlayPauseToggle to simply PauseToggle
add IsFinished and IsPlaying to Timeline
reset Timeline length in Clear
ActionParallel added
fix exception message (copy&paste error...)
Merge branch 'master' into timeline-animation

* master:
  add MatrixHelper.RoundScale
  properly clone Scale, Color, Size and Position in Sprite.Clone()
  glfw target fix so it doesnt crash when the button-array contains less than 3 entries
  mark method added, so the garbage collector is triggered
replaced RoundScale in MatrixHelper with PushMatrixReset
add SoundManager.newSoundCanStopOldest with default True
first draft of the new timeline based animation API
add missing import
optimized some Vector2D instantiation away
typo / nameing fixed
add Looping and play controls (Play, Pause, ..) to Timeline
interface Timeline must extend Updateable