increased default delay slightly before starting background jobs
increased default delay slightly before starting background jobs

from 1 to 3 seconds. This could prevent some sporadic nil errors occuring for tasks that encounter a nil content-blob. Transactions should prevent this, but need to check the default isolation level with mysql.

HITS-SDBV/seek,stuzart/seek,HITS-SDBV/seek,stuzart/seek,HITS-SDBV/seek,HITS-SDBV/seek,stuzart/seek