Add switch code to avatar template
Merge branch 'master' of github.com:guardian/frontend

* 'master' of github.com:guardian/frontend:
  Added JVM Garbage Collection rate metrics.
  Add feature switch for twitter embeds
  Tidy up twitter module
  NL EOF
  Apply styling only when JS is on
  Enhance tweets using Twitter Widgets
  More contrast in neutral statii colour
  Change displayName to title when writing to the content api
  Remove unused placeholder mixin
  Remove fake test comment count
  Improve density of top story patterns
  Fix order to be more efficient