Feature versions for groups

This PR is for improving the version list on the welcome view.

The current problem is, that a user can only see its own changed versions.

This PR solves this problem and is showing all other versions from users which are in the same groups as the current logged in user.
![screenshot 13](https://cloud.githubusercontent.com/assets/1867177/2871239/53d03960-d2fd-11e3-9708-f9da9b6b3594.png)

If no groups are selected it shows only the versions from the current logged in member.