Move config file into test directory.

Also provide a simple configuration file for testing purposes and a worker
submit configuration.
Rename DatasetInfo.ds_label -> label to remove redundancy.
Compress the sandbox again.

Sandbox size was around, e.g., 320 MB and now reduced to 1/6th of this.
Should speed up the work_queue dispatching.
More sophisticated CMSSW release handling on the compute node.

Create a new release that has current release paths needed by scram, and
handle path changes in python files etc...
Compress the CMSSW log file to save some space.
Rework the CMSSW job database structure.

Switch to requesting more than one job at once, while at it.  This will bring
the time for job creation down by an order of magnitude.