First set of changes for DBS3 dataset look-up
Remove cleanup call
Dump args/headers via json.dumps since they're dict; add timestamp to error data dict
Second chunk of changes for issue4009
Extend parse_data to examine type of provided data and make proper decision how to parse it
Update phedex map; require group for dataset4site_group API call, otherwise it's called together with dataset4site API
Check for duplicates records
Extend HTTPError to include system
Add proper system to getdata calls
Add proper system to getdata calls
Split datasets_dbs3 into its own part plus phedex_info; use phedex_info in datasets_dbs2 function too
Merge branch 'issue4009'

It includes changes for replacement of Phedex POST requests to urlfetch ones
for combined data services.