[WIP] Rails 4 upgrade

**DO NOT MERGE YET, WORK IN PROGRESS!**

To get some first feedback I'm already creating this pull request. Of course we will cleanup the commits when it's done for merging.

There will me multiple barclamp pull requests linked against this pull request.
I'm already generating ```crowbar_framework/config/secrets.env``` that gets generated within ```install-chef-suse.sh```. That should stay this way as we want to be able to install crowbar from GIT.