* it is faster.
* it does not require Products.

This avoid having some failures of testnodes

Here the list of changes:
- close all timers when quitting, this makes stopping an erp5tetsnode
  much faster
- remove hack on slapos/testnode after fix of slapos.cookbook
- remove old tmp files left by buildout (buildout has te bo fixed too)
- remove logging handlers where the are not needed any more
- fixed the kill command, it was not able to kill properly childs

There was a sign error in the formula and it lacks code to deal with clock
changes.
Because the watcher will be removed, this patch reverts to imprecise but safe
and simple implementation.