Don't automatically synch. Hitting rate limits.

Other minor cleanups in logic and logging.
also check build if status is pending
ABORTS are no longer spurious

we figured out the reason for the mysterious aborts a while ago
remove stale failure comments when adding tested label
Merge pull request #54 from adriaanm/revert-synching

Don't automatically synch. Hitting rate limits.
Update failure message to explain PLS REBUILD usage better.

Also updated partest/compiler failure detection. Any line
containing "!!", "failure" or "error" (ignoring case) will be
listed in the failure summary.