This reverts commit 6d31793b.

This reverts commit 71560fc5.

Excuse to restart testnode.

Use squid in from of slaptool to cache results.
Return stale values in case of overloaded haproxy.

Synchronous calculation are reactivated because performance should be improved
by new management of software installation.

It will reduce number of activities.

Introduce data caching and avoid re-doing modifications in case if no
important parameter changed.

As simulation and deliveries are less critical, run them less often in order
to give processing power to other tasks.