Extra fields in profile

[cquencer]

Reporetd by Svein W.

Add the possibility to extend the profile with extra fields of various types so that we can set up a more complete profile.

Some of the things in the profile should be possible to add to the profile area of the posts. For support purposes, it could be good to display a flag with the country, maybe timezone (relative to GMT), operating system etc. All this could be set up as extra fields in the profile.