Use timestamps to find unread tickets

Instead of a helper boolean
Use comments directly to detect new notifications
Directly fetch tickets by notifications

and not the notifications themselves
Drop the unread test

There is no explicit operation for marking tickets as unread. Ticket are
now implicitly unread by the comment createtAt timestamps.
Fix Ticket#addComment(...) return value

to be the comment

Also refactor triggerUpdate to Ticket#triggerUpdate(...)
Assert return value from the read api

It's now the Notification object
doc++
Drop obscure helpers.insertTestTickets(...) usage
Better test names
Add /api/notifications #81
Enable require("app/module")
Fix user propTypes
Document models.client.Ticket.Collection methods
Fix title&comment relations in /api/notifications

Did only load them for the first one. This is bit slow since we now
issue two queries for each ticket. I think this can be done using the
withRelated option with some clever SQL hackery.
First version of the NotificationsHub #81
Fix top-buttons for NotificationsHub

Also refactor styles to components
Add global css warning banner
Refactor media queries to sass mixins
Restore comment button styles
Move sidebar styles to SideInfo