[mplayer] redesign to have overlaycontrols frame be as large as the
mplayer window.

previous, MPlayerOverlayControls jframe was a frame only for the overlay
controls themselves.  this posed many problems with mouse movement
detection and other cases that seem to have problems in 1.7.  now
MPlayerOverlayControls jframe fills then entire contentFrame of the
MPlayerWindow.

- changed resizing and positioning code to make overlay frame fill
  parent content frame.
- moved and simplified all input mouse / click handling to MPlayerOverlayControls.
- improved double-click handling for fullscreen toggling
- improved (and fixed) alpha implementation for animation
- fixed Issue#114