Position the navigation above everything else z-wise
fix boder z-index in stacked navigation like the public login
truncate long usernames in the navigation
Merge branch 'design_v4' of github.com:youarehero/youarehero into design_v4

* 'design_v4' of github.com:youarehero/youarehero:
  my quests page WIP
  fixed nav li a overflow