admin: clean-up of Gravatar and IP in user profile headers

Move things around and use Bootstrap compatible markup.

The user IP will rarely be relevant - especially not on the admin pages; the IP
configuration there is more for other user's IP. It might however be somewhat
relevant for a (non-admin) user to know his own IP. There is no obvious place
to show that - it doesn't really fit in as a part of the user profile. Anyway,
just show it under Show Permissions.