Use recent improvements on testnode.
fixed variable name
use cookbook code from erp5testnode branch
increase version of cookbook to avoid 'slap-parameter' already exists errors
use same variable name everywhere
update md5sum of instance-default.cfg
usee newer version of erp5.util to have last testnode changes
Merge remote-tracking branch 'master' into erp5testnode

Conflicts:
	software/erp5testnode/software.cfg
workaround cmmi download directory bug, use shared slapos.cfg
increase version of erp5.util to benefit last bug fixes
Use newer libnetworkcache, required to test eggs using >=0.13.1.
Bump erp5.util version.

Mainly to get erp5.util.taskdistribution fixes.
erp5.util version updated
software.cfg updated.
pin more versions of eggs
increase version of slapos.core
use oldest version of slapos.core until it is fixed
use latest erp5.util
allow to build slaprunner inside an erp5testnode instance
increase version of erp5.util