jenkins stub tile; GH/E clients; secret settings;

added settings.py to repo. now delegates all sensitive settings to
settings_secret.py, which is ignored.

Added a GitHubEnterpriseAdmin and GitHubAdmin that use app keys
(basic auth) to provide read-only admin permissions. (all write
must use the credentials of the actual admin making the change)

disabled autoescape for repo actions so the action can return html.

osw.actions.openSource now only returns an action if the repo is
an enterprise repo.

Added the beginnings of a Jenkins action.
Any extra care needed here to escape the content of `repo.full_name` since `autoescape off`?