add "now playing". missing JS to hide item. :-(

there are some (more or less) native functions out there, called
atv.nowPlaying.willStartPlaying/willStopPlaying/didStopPlaying/playerSta
teChanged/currentAssetChanged/currentAsset to create a hiding script…
but I have dumped too much time here, without a result so far. :-(
fix spelling (please re-hide shared libraries, if needed/wished)
new POT - did we really change that much?
update to latest git