User fullname and avatar are now in an iframe

Great performance boost.

Also:
* Input field to copy @username
  Once we can post, this may be handy
* Search is also an iframe (containing an iframe per user)
  So you can keep composing a twist while searching for usernames
* Should be responsive for cellulars (I can only resize browser
  to check. Got no phone. Anyway, the floating "Fork me" footer
  now has a link to navigation (local users), and that's about all
  the essential navigation. You can scroll a bit down from there
  for search results, or all the way up for the content.
* Make sure Dillo etc. that don't see bootstrap font icon
  can still have text links to everything

Enjoy