Initial support for provisioning SLE12 nodes
Hard-code hostnames in each autoyast file

In SLE12, "hostname -f" doesn't return the hostname we want during
installation. It is correct later on, but not so early.

Since we use a template for each node, we can just directly hard-code
the right value in autoyast.
Do not install any package from crowbar_join

We install rubygem-chef with the autoyast profile now.

As to rubygem-ruby-shadow, it's not needed anymore as we fixed the bug
that required it to be installed early. See
https://github.com/crowbar/barclamp-pacemaker/commit/230f2a161ea220d6c1c2d51b438d1419759edbe0
Merge pull request #332 from vuntz/sle12

Initial support for provisioning SLE12 nodes