run: set up archive dir and logger output sooner

Signed-off-by: Sage Weil <sage@inktank.com>
test
Move logging setup out of main()
run: write info.yaml on job start

Include basic metadata bout the job.

Signed-off-by: Sage Weil <sage@inktank.com>
Add exception hook
Pretty-up write_initial_metadata; s/run/name/
Don't print colon if there's no exception message. Also, remove testing
exception.
Workers: only log child's stderr, not stdout
Merge pull request #61 from ceph/wip-logger

Log all the things! (Things like exceptions.)
run: do not import at top level

This makes a run with --lock hang when connecting, for some
reason.  E.g.,

 $ teuthology -v a.yaml --lock
 ...
 INFO:teuthology.task.internal:Opening connections...
 DEBUG:teuthology.task.internal:connecting to ubuntu@plana06.front.sepia.ceph.com
 <hangs>

No clue what is going on here, but this fixes it!

Signed-off-by: Sage Weil <sage@inktank.com>