Server based backend

[Rene Ranzinger]

Implement an alternative backend system that is based on a server. The GUI requests and displays data from the backend rather than the file system. This should be an alternative to the filesystem that a user can select.

The sever implementation should be available to the community as well and allow each group to install their own common shared backend.

This will need additional considerations with regards to data synchronization between different clients. But at the same time open the way for versioning (auditing) changes.