Use a proper icon when the server does not provide it

*In the now playing fragment use iradio_noart for remote streams otherwise
 album_noart. Also use a larger icon for the full heigt layout and a smaller
 icon otherwise.
*Try to figure out which icon to use for plugin items (currently internet
 radio stations and favorites.
Fix constantly updating the power state
Fix dynamically change visible/enable for action bar items

Use ActionBar.findItem instead of Menu.findItem, so items on the action bar can
dynamically change visibility and enabled/disabled, on pre honeycomb devices,
i.e when using the actionbar compatibility code.
Merge commit 'e54597e495a591e50c357eb3f1a31e2b4b86af7a' into actionbar

* commit 'e54597e495a591e50c357eb3f1a31e2b4b86af7a':
  Fix dynamically change visible/enable for action bar items
  Fix constantly updating the power state
  Use a proper icon when the server does not provide it

Conflicts:
	src/uk/org/ngo/squeezer/itemlists/SqueezerAlbumArtView.java
	src/uk/org/ngo/squeezer/itemlists/SqueezerPluginItemView.java