Make presubmit.py rules differential.

Make presubmit.py rules differential.

This turns the absolute list of linter rules within the presubmit.py
wrapper into a list relative to the default of the cpplint.py script.
This has the advantage that new rules are picked up when the script is
updated and that allowed violations are visible from the list.

R=machenbach@chromium.org

Committed: https://crrev.com/77e40bc5f3227f8bdeba9de6e7fa363ec5ed4f8f
Cr-Commit-Position: refs/heads/master@{#30513}

[Michael Achenbach, 2015-09-01 13:40:27]

LGTM - please clobber the lint cache and run this locally to ensure we're not
picking up formerly untested rules.

[Michael Starzinger, 2015-09-01 13:50:36]

Thanks! Yep did so, ran "rm .cpplint-cache; ./tools/presubmit.py" locally.

[Michael Starzinger, 2015-09-01 13:57:48]

The CQ bit was checked by mstarzinger@chromium.org

[commit-bot: I haz the power, 2015-09-01 13:57:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1325833005/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1325833005/1

[commit-bot: I haz the power, 2015-09-01 14:28:27]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-01 14:28:45]

Patchset 1 (id:??) landed as
https://crrev.com/77e40bc5f3227f8bdeba9de6e7fa363ec5ed4f8f
Cr-Commit-Position: refs/heads/master@{#30513}