Fullscreen improvements

- fix sizing error so that the image actually fits the screen
- hide some stuff that didn't work properly in fullscreen anyway
  (commons/survey buttons just exited fullscreen, reuse menu
  did not fade with the metadata panel, view terms link didn't do
  anything)
- move metadata scroller CSS rules into metadata scroller LESS file
- disable invite animation which broke the opacity transition
- move opacity transition to the main metadata panel element;
  remove background-color transition which is pointless since there
  is an opacity transition

Change-Id: Ib26160cc6431ea007dab8441c634d0faf9ee1d0a