support Google Analytics subdomains and multiple top-level domains tracking
fix KeyError at localwiki-manage setup
Fix the VERSIONUTILS_VERSIONING_ENABLED setting.

Prior to this fix, the setting wasn't really working anymore because we weren't
created a .versions() manager on models.
Dont m2m_changed signl if instance isnt versioned.
apt-get update before everything
fix #513 - move GOOGLE_ANALYTICS_ID into constance
move all (new) GA settings to constance