KVM SR: fix tunnel generation.

Was tunnelling to the wrong port.
KVM SR: Fix virtual-hard-drive-md5sum parameter.
KVM SR: Publish IPv6.

Used to access directly to VM.
KVM SR: add resiliency test structure.
Simplify resiliency workflow.

Why having wrappers of wrappers of wrappers, when we can have simple, readable code?
Resiliency: allow takeover script to be configurable.

Add a way to takeover remotely.
Resiliency: Add backup-periodicity parameter support.
KVM SR: setup small backup periodicity for resiliency test.
KVM SR: Change number of backup to 2.
Resiliency: fix takeover script.
Merge branch 'kvm'
Release slapos.cookbook-0.81.
Advertise development of new version