appbar 6.x-2.0-alpha1

This is the new, experimental branch of the Application Toolbar. It works, it seems stable to me, but I advise testing before use on production sites for now.

Sites upgrading from 1.x must delete the entire appbar module folder before upgrading to the new version. After upgrading, you must also run update.php.

Compared to the 1.x branch, this release:
- Drops the Default Alerts submodule (use Rules [preferred] or Trigger to create new alerts)
- Allows using blocks in the Appbar
- Drops the concept of "bar regions" and "alert types"

The result is much more power and flexibility, although you will have to do more setup to get alerts working because you have to build the Rules to set the alerts yourself.