/reviewed-on nexedi/slapos!172

  Simple Don't repeat yourself.

Otherwise, performances get awful on HDD, and not far better on SSD.

resilient: adds a promise to test integrity and the status of the last run of the feeds generated by notifier scripts

Also deploy takeover script only in import instances. This is non-sense to deploy it on export/pbs instances.

It will be used by equeue to prevent to run import scripts if detected.
Reason: if an import script is run AFTER takeover has been done, it may be stopped during its execution while slapgrid is run, causing the new-main instance not to behave correclty.

Allow to run inside of a slapproxy w/ all partitions using same IP.

Do Not Push The Big Red Button.

Resilient stack: define different ssh/httpd ports from pbs, import and export. Allow to have import/export using same IP.

So that we publish ony once, not twice.

This is a squash merge of 'resiliency-testing' branch when
the HEAD of this branch was f725c81d7d69.

The merge was done by Antoine Catton.