control structure where a process/program has been made aware of the job(s)
they are responsible for controlling.  This is facilited via a job url:
   mysql://ia64e:3306/jessica_compara32b_tree/analysis_job?dbID=6065355
AnalysisJobAdptor::CreateNewJob now returns this url on job creation.
When a job is datflowed, an array of these urls is returned (one for each rule).
Jobs can now be dataflowed from a Process subclass with blocking enabled.
A job can be fetched directly with one of these URLs.
A commandline utility ehive_unblock.pl has been added to unblock a url job.
To unblock a job do:
   Bio::EnsEMBL::Hive::URLFactory->fetch($url)->update_status('READY');
This is primarily useful in asynchronous split process/parsing situations.