4teamwork/opengever.core — pull request #652 by phgross (2014-11-06 09:13:06+00:00)
Title: Add new type Inbox Container

Added new type InboxContainer. Which is used in setup's with multiple `OrgUnit's` per `AdminUnit`, to store all inboxes (each for every `OrgUnit`).

This way of implementations is the better alternative, than the previous implementation with a `Maininbox` containing all `Subinboxes`. Because an specific container type brings the following benefits:
* It's not possible to create content on the `InboxContainer` respectively `MainInbox`.
* The permissions are much better understandable.
* A user wich has access to an inbox, but not on the inbox of the current `OrgUnit`, can be informed with an status message.

@lukasgraf @deiferni please have a look.