Clean up extreme verbosity of logs in test harness.

In addition fix a bug where we track the wrong parallel job on the job pool.

In addition fix bug where we unittest harnesses randomly hangs while trying to write to stderr while finding update candidates.

Change-Id: I1449501606a57c5324eafc74c4fc388fbbe2bee3

TEST=Ran with -q and full test suite and emulated errors
when necessary to see errors printed out only failures.

Review URL:
8 files changed