Rephrase analytics index
Add analytics_ua field on Site
Move DEBUG ua to settings and return correct site UA in context processor
Add initial ua form in admin UI
Add info-section on how to find the ua code
Restructure the page layout
Include GA shared account details in view
Implement analytics ua form
Hide form by default if ua code exists
Default UA value to empty string
Hide Google Analytics scripts if UA is not set
Don't assume Google Analytics is always enabled
Merge branch 'analytics-ua'