ui: context/vocabulary revamp: fixing showstoppers

commit e9a20923a1e6d286b7c702df60ca4aa2a458b18a
Author: Max F. Albrecht <1@178.is>
Date:   Mon Jun 2 13:18:38 2014 +0200

    vocabulary: make group of keys horizontal

commit 0f8b6378787558bd6d71e6412978f51a3c8f8b85
Author: Max F. Albrecht <1@178.is>
Date:   Fri May 30 17:37:35 2014 +0200

    my/dashboard: swap user_contexts and welcome message

commit af7949e15ce734df85c49fa539b4262b97f66894
Author: Max F. Albrecht <1@178.is>
Date:   Fri May 30 17:05:34 2014 +0200

    wrap vocabularies listing in proper rows

commit d938b7a7a1eb681d5abb64ed38e486884d8555d3
Author: Max F. Albrecht <1@178.is>
Date:   Fri May 30 17:04:48 2014 +0200

    when showing contexts, don't crash if a key has no terms