Add user profiles.

[mnowotka]

Currently a user can log in and log out and curation interface fills created_by and updated_by fields when necessary. This is useful but the auth django app that is used to do this stores following information about user:

• first name
• last name
• user name
• email
• password hash

There should be a new item in the top menu available after clicking on user name. The title should be something like 'edit user profile'. Clicking on it should present a dialog where the user can edit:

• first name
• last name
• email
• password

user name should never be editable to keep track of user activities all the time.

The separate topic for (far) future is sending email confirmations to check if the email is valid and supporting different authentication mechanisms (oauth/LDAP/shibboleth).