Roll tools/swarming_client/ to b39a448d8522392389b28f6997126a6ab04bfe87.

Roll tools/swarming_client/ to b39a448d8522392389b28f6997126a6ab04bfe87.

$ git log f222001cc..b39a448d8 --date=short --format='%ad %ae %s' | sed 's/@chromium\.org//'
2015-05-11 maruel Fix crash when exit_code=='N/A'.
2015-05-04 maruel Handle SIGTERM while uploading results back.
2015-04-27 phajdan.jr Don't use parent of root_dir as temp directory
2015-04-22 maruel Trap TypeError in collect when trigger had failed.

R=vadimsh@chromium.org
BUG=

Committed: https://crrev.com/adfd60769038bf8dd1ba8cc5c3be52b9c0058154
Cr-Commit-Position: refs/heads/master@{#329321}

[Vadim Sh., 2015-05-11 23:32:21]

lgtm

[M-A Ruel, 2015-05-12 01:03:00]

The CQ bit was checked by maruel@chromium.org

[commit-bot: I haz the power, 2015-05-12 01:06:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1131013003/1

[commit-bot: I haz the power, 2015-05-12 02:14:40]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-12 02:15:25]

Patchset 1 (id:??) landed as
https://crrev.com/adfd60769038bf8dd1ba8cc5c3be52b9c0058154
Cr-Commit-Position: refs/heads/master@{#329321}