Add popup help to web user role permissions.

Notes:

1. I copied `makeHqHelp` from the new `COMMCAREHQ` to the legacy. Presumably this won't cause trouble but simply be ignored, but let me know. 

2. I was not sure about lifting the binding up to a common base template, so that found in `users/users_base.html` duplicates that found in `app_manager/apps_base.html`