Playing a streaming track causes Panels to reset

[Brian Parma]

When a new (http) streaming track is started, the panels (like collection) reset, which automatically collapses the tree.

According to IRC sources this is because track data is refreshed for streaming tracks, which causes track_tags_changed event to be fired, which refreshes the panels.

While not critical, it is annoying to have the track list collapse each time you play a track.

[reacocard (reacocard)]

Fix for this bug is to add a couple of checks in the callback for track_tags_changed to ensure that
1) the passed track is a member of the Collection the panel represents
2) the tag that changed is one of the actively displayed tags

[reacocard (reacocard)]

fixed trunk/2786