Fine tune controls hover animation (#526)

As in fullscreen the slim mouseout timeline is not below the container -
bottom: 0 - but bottom: 3px there is a vertical jump of the timeline in
the mouseover to mouseout transition: During the hide delay of .3 secs
the still visible timeline as part of the controlbar is 'pushed up'.

To prevent this:
- bottom transition for fp-controls in fullscreen mouseout state
- opacity transition to 0 for fp-play fp-time fp-volume in fullscreen
  mouseout state - with a delay of 0 so the widgets are not visible when
  timeline already has disappeared
- reinstate the opacity transition with the default hide delay for
  fp-time of aside-time players