Tab reordering and IMAP improvements

Now that we have a nice logo and artwork (well, my opinion), new improvements appear:

Bug 105885:
Reorder / Rearrange / Move tabs in the Suite's tabbed browser

Bug 308988:
support delegated use of imap shared folders

Habemus logo

Finally, the new logo and artwork has been chosen. If you ask me, I can perfectly live with it. Looks nice! :-)

For more information, see Bug 312994.