Layout changes - toolbars and search bars

* Adds a second toolbar below the main one, to hold the location/path bar.

* Makes search bars slot-dependent.  This means you can have individual search bars visible for each pane or tab you have active, and the views make more sense.  This should address #32.  If I've misconstrued the intent, let me know and I'll adjust.

Screenshot: http://dl.dropbox.com/u/8201170/layoutchanges.png