PERF: don't render user card until displayed
PERF: don't render share dialog until we have a link.
PERF: don't render composer until we need it
FEATURE: support for emoji sets

Added following emoji sets
  - Apple/International
  - Emoji One (default)
  - Android/Google
  - Twitter

FIX: translations from plugins weren't properly merged with default translations
FEATURE: new 'site_setting_changed' event