[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.
Currently it's generated in install-chef-suse.sh and loaded within the init script. But with dotenv-deployment gem i've got a much better idea. I will generate crowbar_framework/config/crowbar.env.production while package install and this gets already loaded by the mentioned gem :)