This revision addresses the issues with the previous patch raised by Pádraig
Brady. Namely:
* Creating a new hook now sets the `Location` HTTP header properly
* `version` is stored in the database and displayed whenever a hook XML is shown
* Made aeolus-conductor.spec.in aware of the newly-added views
* Updated and simplified the tests
Note that as before, this implements only the registration portion of the
notification API. Sending events will happen post-1.0.
Thomas