Add CLOUD_VERSION env var

Allows to switch between Cloud releases (currently either 2.0 or 3).
Add Devel:Cloud:Shared:11-SP3.repo

IBS repo layout changed recently. Set some priorities to make sure
Devel:Cloud projects overrule SLE repos and install media.
Configurable path for mirrored media

Control freaks mirror media to various directories (like /srv/nfs/media)
and want to expose that to VM guests.
crowbar-prep.sh: add -r option for setting sledgehammer root pw
crowbar-prep.sh: check we have a FQDN
crowbar-prep.sh: ensure commands succeeded
crowbar-prep.sh: rename misleading sc2_repo variable
crowbar-prep.sh: minor tweaks to versioning

Add new --product-version switch.
Cleanup testrepository leftover files

Data from previous runs piles up and eats up disk space (neutron had
7G). So the data of the current run is kept for debuggability.
Put someone's fiddling in git

Combination filter changed in the web interface.
Remove many client unit tests

The following list of clients now run unit tests during RPM build:

    python-designateclient
    python-ironicclient
    python-marconiclient
    python-openstackclient
    python-troveclient
    python-tuskarclient

This already revealed several issues.
Add some crowbar client nodes to /etc/hosts

For easier ssh matters
Add "intr" option for NFS mounts

Allows to abort hanging NFS calls (that otherwise wouldn't be
interruptible due to the "hard" default option).
Set NFS mount r/w operation default blocksize to 8k

Should obtain better performance.
Allow having "rw" NFS mounts.