File->Join Tabs experiment. Can disable through prefs.js, and I may make disabled...

File->Join Tabs experiment.  Can disable through prefs.js, and I may make disabled the default before we branch trunk depending how things play out.  One current limitation is that the interfaces thus joined get reloaded as a consequence of their respective DOM nodes being relocated, so tab joining is most useful to setup prior to retrieving information you'd like to view side by side.  I haven't found an easy way around this, though we could roll our own tab browser (bleh) or come up with a generic way for interfaces to save their state.  Tab labels are also imperfect, given that interfaces are able to dynamically modify the tab label and can clobber each other if sharing a tab

git-svn-id: svn://svn.open-ils.org/ILS/trunk@16830 dcc99617-32d9-48b4-a31d-7c20da2025e4