UI: System messages, Stream messages and button progress indicator
Merge branch 'ui-dev' into buckets-ui-dev
Implement bucket settings

* The bucket name and display settings of the bucket are now
modifiable via the settings page. Changing the name of the bucket
triggers a redirect to the settings page using the URL slug generated
from the new bucket name
Remove unnecessary controllers

* Controller_Bucket_Collaborators and Controller_Bucket_Display
are no longer required because the bucket settings page now makes
use of tabs so all the content is preloaded into the view and JS is used
to switch between the different containers - options and collaborators
Remove unused routes
Collaborators modal dialog

* Basic wiring for the dialog to be used for adding
collaborators