Include CMS user account in profiles -- dup emails

If you choose to include CMS user account form fields in a profile, the email address field must be included in the profile. When the profile is used for inclusion in a contribution page (e.g. membership signup) or event page, that results in a duplication of the email address, as the email address is hardcoded into those forms to begin with.

The profile form should check for the presence of the email address in the profile OR in the containing page element before disabling the user reg fields.