Roll tools/swarming_client/ to 02196398776eff7d735a499e21cd644d5c3faf91.

Roll tools/swarming_client/ to 02196398776eff7d735a499e21cd644d5c3faf91.

$ git log a57d7db40..021963987 --date=short --format='%ad %ae %s' | sed 's/@chromium\.org//'
2014-10-17 maruel Add --idempotent support now that the server supports it.
2014-10-17 maruel Fix a client side failure when a task completely blows up.

TBR=vadimsh@chromium.org
BUG=

Committed: https://crrev.com/832d503e9344768285c74f58106430b6b515cc0c
Cr-Commit-Position: refs/heads/master@{#300492}

[M-A Ruel, 2014-10-21 12:31:55]

The CQ bit was checked by maruel@chromium.org

[commit-bot: I haz the power, 2014-10-21 12:35:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/666673008/1

[commit-bot: I haz the power, 2014-10-21 13:59:00]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-10-21 13:59:01]

Try jobs failed on following builders:
  linux_chromium_rel_swarming on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[M-A Ruel, 2014-10-21 14:02:37]

The CQ bit was checked by maruel@chromium.org

[commit-bot: I haz the power, 2014-10-21 14:03:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/666673008/1

[Vadim Sh., 2014-10-21 14:11:53]

lgtm

[commit-bot: I haz the power, 2014-10-21 15:48:51]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-21 15:49:35]

Patchset 1 (id:??) landed as
https://crrev.com/832d503e9344768285c74f58106430b6b515cc0c
Cr-Commit-Position: refs/heads/master@{#300492}