* Made GrailsJobClass complete; description,
persistJobDataAfterExecution and name can now be set on a job. 

def name = 'MyJobName' 
def persistJobDataAfterExecution=true
def description = 'My foobar description of job'

These are set on the SimpleJobDetail 

* SimpleJobDetail should extend JobDetailImpl, because RamStore cast to
JobDetailImpl to update the datamap if it should be persisted