timeout stuff moved into AbstractStateMachine
service jobs are no longer parallel executed
InitiatorDispatcher implemented to separate handling of job types
bugfix: redundant initiator feedback removed
PgServer.DEFAULT_PORT -> PG_PORT
LoaderSessionInitiator.dataSourceBusy parameter removed
Loader: explicit tracking of busy data sources implemented
don't acknowledge job until loader session is actually started

This ensures that the requested data source is properly marked to be
busy by the loader before another job is initiated which potentially
applies the very same data source.
Merge pull request #102 from IDgis/job-exec

service job execution fixes