New user import fully working

A new user's profile can now be completely imported from
an external service, such as LinkedIn, MyUSA, or others.
Tested with LinkedIn.

This only applies to new users, who sign up through one of the
login OAuth services.  When this happens, it will extract
skills, topics, location, company, title, bio, name, email, etc.
This should make it much easier for a user to sign up.

This is also needed for Corridor @ State, where we should be
able to import an existing user's Corridor profile using the
same technique.  See config.js to see how the fields are set.

There's a new config file, config/settings/tags.js that needs
to be copied from tags.ex.js.  This has the setting for
whether tags should be created if they don't exist on a user
import.