Pan Update

I've made some more progress on Pan. Here is yet another snapshot.

• removed pan-object.
• removed pan-callback.
• convert newsrc to g_object.
• convert identity to g_object.
• turn queue into dummy object for its signals.
• lots of related bug fixes.

I still need to work on queue so that the rules & dialogs will compile. Bassically that's were I'm at - compile, see what breaks & try to fix it.

r233