#10012 - Profile.module:

- Restoring broken update path.
- Adding birthday/date function back, with update path.
- Show private fields when viewing your own profile, or for admins.
- Do not allow browsing of private fields for non admins (403)
- Throw a 404 for browsing unbrowsable fields, rather than an SQL error
- Fixing input processing: nothing is filtered twice anymore, and I replaced several strip_tags with specialchars (more flexible).
- Minor admin UI tweaks + added friendly field type names.