I've added two settings to codereview.settings - LINT_REGEX and 
LINT_IGNORE_REGEX - to specify which files should be linted. The default
is to lint anything that ends in .cpp, .cc, .inl, or .h, and to ignore 
nothing.

I have also modified GetCachedFile() to look for a locally modified version 
of codereview.settings before looking in the repository.

  R=maruel@chromium.org
  TEST=none
  BUG=none

Review URL: http://codereview.chromium.org/257054

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@30415 0039d316-1c4b-4281-b951-d872f2087c98