Globally ignore '*_excluded' keys for MSVS Settings

This extends validation of MSVS settings to ignore any key found that is suffixed with '_excluded', but still verifies that the root key name is a valid setting.

Patch from Eric N. Vander Weele <ericvw@gmail.com>

R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/175873002

git-svn-id: http://gyp.googlecode.com/svn/trunk@1858 78cadc50-ecff-11dd-a971-7dbc132099af
1 file changed