#67 Implemented the feature to skip back animation ...

based on MagnetRONFrame#skipBackAnimation() (may be  thread bug).
Added SkipBackAnimationAction.

#67 Implemented the feature to fast forward animation ...

based on MagnetRONViewer#animationSpeed.
Added FastForwardingAnimationAction class.

Forgot to commit at point enabled to change the language.

Enabled to change the language of names such as MenuBar.