fixing shift up/down in library. closes #46.
send update to client when replaygain scan completes
importURL: URI decode filename

Fixes _20 etc showing up in filenames.
client: fix displaying incorrect track number

when the track number is not known.
client: fix library items not always expanding consistently
ability to attach and detach encoder and player.

 * admin option to disable and enable hardware playback. Closes #129
 * only attach encoder when streamers are connected. Closes #143
add debug thing
more reliable headless playback
debug stuff