removed bad function, merge from latest master
fixed test_claim_objects test to use sample data
removed commented out test
throttled unit tests to 250 sample items
made the long test only run if '--runslow' option is used
made 'load_job_data' expect a single job in the blob
fixed sample_data_generator to generate single job, rather than list of them per blob
added revision_hash field to objectstore.
merge from jobs-derived-models