Merge pull request #335 from dirkmueller/master

Switch to Cloud-5 based repositories
Add Cloud repos for SLE-12 nodes
Fix autoyast package list for SLE 12 nodes

The release packages for the SLE 12 Cloud image have a different name
Merge pull request #337 from rhafer/sle12-autoyast

Sle12 autoyast
We just need the target platform version in the template

Rework the version check to be on the safe side for a future SP4 update for
SLES 11.
Use systemctl on SLES12 to enable chef-client
SLES12 uses a different mechanism to enable/diable core dumps
Set hostname in autoyast network config

This seems to be needed on SLES12, otherwise the hostname is not configured
correctly when crowbar_join.sh is running.
Merge pull request #338 from rhafer/sle12

adjustments to get crowbar_join.sh SLES12 succeeding
crowbar_register: Make the check for SLE12 more future proof

This is basically the same as f96652697, just for crowbar_register
Fix crowbar_join installation on SLE12 nodes

The crowbar_join.sh as installed on the client nodes was still using
wrong sntp command line on SLE12 because we didn't pass the template the
target_platform_version parameter.
Merge pull request #341 from rhafer/sle12

crowbar_join and crowbar_register fixes for SLE12
Tighten check for HAE repos

Just an empty directory is not enough, there should be
repomd metadata in there. so check for the availability
of the metadata.