Comment 9 for bug 1090685

Work as expected here,thanks.
Some minor things:
* In other single button views (Recordings), we have buttons aligned from the right to left side. It is reversed here.
* Add a hint to the tooltips, that you first have to select a track before you'll be able to perform an action.
  Purge Buttons:
  "Purge selected tracks from the library."
  Unhide button:
  "Unhide selected tracks from the library."

For a moment a thought about additional "Select all" and "Rescan Library" buttons in there, but now i'm not completely sure if they are useful. Opinions?