Add stats script.

Add stats script.

This includes some feature additions and bug fixes:
- Add additional date modifiers.
- Handle case where patchset is missing from an issue.
- Fix date issue that occurs with some CLs.
- Add support for importing 'stats' and calling its methods.
- Add BERSERK and BINARY_FILE2 message handling.
- Add FAILED_PATCHSET and INTERNAL_ERROR message handling.
- Add APPLY2 message handling.
- Change number of items per search to 100.
- Make output unbuffered.
- Change the QPS throttle to allow up to 20 QPS.

Also some extra changes:
- Add script to call stats.py.
- Ensure all lines are < 80 chars and indent is +2.
- Add skia tracking.

Original author: eseidel@chromium.org
Modifications by: ilevy@chromium.org
Further modifications by: cmp@chromium.org

TBR=eseidel@chromium.org
BUG=330869
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=242625

[commit-bot: I haz the power, 2013-12-27 18:06:34]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/cmp@chromium.org/121763002/1

[commit-bot: I haz the power, 2013-12-27 18:06:55]

Presubmit check for 121763002-1 failed and returned exit status 1.

Running presubmit commit checks ...

** Presubmit ERRORS **
Pylint (35 files) (8.62s) failed
************* Module stats
F0401: 12,0: Unable to import 'numpy'
F0401: 15,0: Unable to import 'requests_cache'


Presubmit checks took 16.0s to calculate.

Was the presubmit check useful? Please send feedback & hate mail to
maruel@chromium.org!

[commit-bot: I haz the power, 2013-12-27 18:13:07]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/cmp@chromium.org/121763002/1

[commit-bot: I haz the power, 2013-12-27 18:13:28]

Change committed as 242625

[eseidel, 2013-12-27 18:15:27]

Thanks!  Glad this was useful!