Add subunit2sql gearman workers

This adds a new gearman worker to process the subunit files from
the gate job runs. It will use subunit2sql to connect to a sql
server and process the data from the subunit file. The
log-gearman-client is modified to allow for pushing subunit jobs
to gearman, and the worker model for processsing logs is borrowed
to process the subunit files.

Change-Id: I83103eb6afc22d91f916583c36c0e956c23a64b3
Merge "Add subunit2sql gearman workers"