TASK: Persist after package
TASK: Persist after package

Adds a PersisteneceManager:persistAll() after processing
a package. When starting the importer on an outdated
database, the importer takes hours and crashes on memeory
limits - the persistAll cleans up memory and a re-run
skips already update packages.

dfeyer/Neos.MarketPlace,neos/Neos.MarketPlace,neos/Neos.MarketPlace,dfeyer/Neos.MarketPlace,neos/Neos.MarketPlace