Allow users to customize the sanity-checking regexes

Allow users to customize the sanity-checking regexes

This doesn't add security, but at least allows users to open up the
regexes where it's safe to do so.  Fixes #985.

Tested by hand.

Patched from https://github.com/buildbot/buildbot/commit/cea9873e7fbe793720e55043c1c7fc4aebff0bd9.

BUG=541449
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=297551

[smut, 2015-11-13 21:43:46]

Description was changed from

==========
Allow users to customize the sanity-checking regexes

This doesn't add security, but at least allows users to open up the
regexes where it's safe to do so.  Fixes #985.

Tested by hand.

Patched from
https://github.com/buildbot/buildbot/commit/cea9873e7fbe793720e55043c1c7fc4ae....

BUG=541449
==========

to

==========
Allow users to customize the sanity-checking regexes

This doesn't add security, but at least allows users to open up the
regexes where it's safe to do so.  Fixes #985.

Tested by hand.

Patched from
https://github.com/buildbot/buildbot/commit/cea9873e7fbe793720e55043c1c7fc4ae....

BUG=541449
TBR=
==========

[smut, 2015-11-13 21:59:51]

Description was changed from

==========
Allow users to customize the sanity-checking regexes

This doesn't add security, but at least allows users to open up the
regexes where it's safe to do so.  Fixes #985.

Tested by hand.

Patched from
https://github.com/buildbot/buildbot/commit/cea9873e7fbe793720e55043c1c7fc4ae....

BUG=541449
TBR=
==========

to

==========
Allow users to customize the sanity-checking regexes

This doesn't add security, but at least allows users to open up the
regexes where it's safe to do so.  Fixes #985.

Tested by hand.

Patched from
https://github.com/buildbot/buildbot/commit/cea9873e7fbe793720e55043c1c7fc4ae....

BUG=541449
==========

[smut, 2015-11-13 22:02:03]

smut@google.com changed reviewers:
+ agable@chromium.org, sergeyberezin@chromium.org

[smut, 2015-11-13 22:02:03]

I've added you as a reviewer because you're in the git log for people who have
touched third_party/buildbot most recently.

Rationale for this is that I have a builder where I need to allow newlines in
the value of one of the properties that will be passed to the builder via the
"force build" form. This patch allows masters.cfg to set arbitrary regexes which
properties on that form must adhere to instead of hard-coding it.

[Sergey Berezin, 2015-11-13 22:22:56]

I can't claim to fully understand the code, but if it works and is part of the
official buildbot now, LGTM.

[smut, 2015-11-13 22:37:37]

The CQ bit was checked by smut@google.com

[commit-bot: I haz the power, 2015-11-13 22:37:42]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1440163005/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1440163005/1

[commit-bot: I haz the power, 2015-11-13 22:56:35]

Committed patchset #1 (id:1) as
http://src.chromium.org/viewvc/chrome?view=rev&revision=297551