Add and retrieve notifications for a user
Get notifications for all favourites
API to drop and collect notifications for each favourited topic
Fix test
Notification are now a distinct object type

This allows us to story properties against all notifications (Eg,
headline, date ...)
Getting all notifications is convoluted, so I've removed it
API now understands notifications
Ability to clear notifications
Tidy comments
encodeURI all the uuid parameters

The bodyParser automatically does this when POSTing, so when you issue a
GET for the same resource it needs to be encoded in the same way.
Merge pull request #22 from Financial-Times/notify

Notifications