Add a //nogncheck anntation to GN include checker

Add a //nogncheck anntation to GN include checker

The include checker will now skip includes annotated with "// nogncheck" which allows some edge cases to be worked around while still running the check pass on the rest of the includes.

This also updates the reference docs to the latest version.

Committed: https://crrev.com/20982dc0654c13678837bdb4c08e1bcc94248fcf
Cr-Commit-Position: refs/heads/master@{#337499}

[brettw, 2015-07-06 21:59:05]

brettw@chromium.org changed reviewers:
+ dpranke@chromium.org

[brettw, 2015-07-06 21:59:09]

The CQ bit was checked by brettw@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-07-06 21:59:24]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1217093007/1

[commit-bot: I haz the power, 2015-07-06 22:15:08]

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

[commit-bot: I haz the power, 2015-07-06 22:15:08]

Dry run: This issue passed the CQ dry run.

[Dirk Pranke, 2015-07-06 22:24:43]

lgtm

[brettw, 2015-07-06 22:27:05]

The CQ bit was checked by brettw@chromium.org

[commit-bot: I haz the power, 2015-07-06 22:28:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1217093007/1

[commit-bot: I haz the power, 2015-07-06 22:37:15]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-06 22:38:11]

Patchset 1 (id:??) landed as
https://crrev.com/20982dc0654c13678837bdb4c08e1bcc94248fcf
Cr-Commit-Position: refs/heads/master@{#337499}