Add tag list to user profile

[Jef van Schendel]

Currently the left part of the user's profile only contains... the
profile.

It'd be great if below that, we could have a list of tags they've
used.


-  Maybe with a number behind it telling you how many times they've
   been used.
-  If there are a lot of tags, say, more than 20 or 30, the list
   should be cut off.
-  Of course each of these tags should link to the /u/tag/X page
   and list all of the media with that tag.
-  Maybe we can add a "show all" link that links to a full page for
   the user's tags. Maybe a tag cloud there?

    **schendje's profile**¶
    -----------------------

    I like swimming and eating pasta. Preferably at the same time.

    +----------------------------------+
    | **Favorite tags** (show all)     |
    +==================================+
    | spain (8) sky (5) cows (4)       |
    +----------------------------------+
    | portrait (4) self-portrait (3)   |
    +----------------------------------+