qa_crowbarsetup: reenable ha repos for cloud3+

Readd HA repositories when using Cloud3 or Cloud4. This was accidentally
remove in 2e35584049.
Merge pull request #159 from toabctl/readd-cloud3plus-ha

qa_crowbarsetup: reenable ha repos for cloud3+
qa_crowbarsetup.sh: Add support for SLE12 Compute media for susecloud/Mx
Merge pull request #160 from dirkmueller/master

qa_crowbarsetup.sh: Add support for SLE12 Compute media for susecloud/Mx
qa_crowbarsetup.sh: Don't modify DNS proposal before node allocation
qa_crowbarsetup.sh: Stop creating DNS proposals

The DNS propsal always exists, we just need to update it instead
of trying to create a new one.
qa_crowbarsetup: Always setup SLE12 repositories for Cloud 5+

This allows e.g. the QA team to manually go in and install more than
one SLE12 node.
Merge pull request #161 from dirkmueller/master

fixes for multi dns tests
qa_crowbarsetup.sh: The naming layout for M3 changed
qa_crowbarsetup.sh: Treat Mx as Cloud 5.x for now