Get oauthappid from 'values'.
If oauthappid is specified in the app's configuration panel (see configurationPanel.js), then it will be accessible through the 'values' property.
Special handling of 'localhost' for the auth cookie.
Merge pull request #8 from robert-claypool/upstream

Special handling of 'localhost' for the auth cookie.
fixes #9
Merge pull request #7 from robert-claypool/master

Get oauthappid from `values`
We can just use lang.mixin instead of lang.safeMixin.