Notes

Implemented support for Notes;
- A note belongs to a Story, and is only visible in the Story-Task-view
- Editors and Admins for an area have all permissions, that is, create/delete
- To create a note for any story (in any area) the used needs to be logged in. A logged in user must be Editor/Admin for the area where to which the story belongs in order to be able to remove notes for that story
- Anyone can read notes
- Notes can be generated by the system, e.g. when a story is archived
- Note-events are pushed out to clients