win: support linker warnings-as-errors

R=thakis@chromium.org
BUG=310938

Review URL: https://codereview.chromium.org/102593004

git-svn-id: http://gyp.googlecode.com/svn/trunk@1805 78cadc50-ecff-11dd-a971-7dbc132099af
Ignore pylint blacklist on Windows too

I'd been cursing pylint on every dcommit for the last year or
so and then doing --bypass-hooks. This seems an improvement.

R=thakis@chromium.org

Review URL: https://codereview.chromium.org/104683005

git-svn-id: http://gyp.googlecode.com/svn/trunk@1806 78cadc50-ecff-11dd-a971-7dbc132099af