ThinkUp LLC hosted app redesign

TODO:
* Redesign OSP admin views for plugins other than Facebook and Twitter
* Delete old dashboard and menu interfaces, classes, registrars, tests
* Add missing test coverage
* Clean up code
Avoid mixed content warnings when running app on SSL
Email redesign assets [ci skip]
Email redesign
Email fixes - Date, header copy, unsub link
Reintroduce privacy setting
Utils function to determine if ThinkUp LLC endpoint is set
Set from and unsub link in email notifications from thinkup.com correctly
Implement random subject lines and header text in insight notification emails
Fix randomizer range bug
Set from: address to team@thinkup.com for ThinkUp LLC
Session login API: don't include success message on successful redirect
Make email notification footer copy more informative
Flashback insight: Add missing period, clean code, add tests
Add Settings to navigation menu
Insight email notifications: New, temporary beta message and a reply note in the footer
Insight notification email fixes
- URL-encode network username and network on insight headline links
- Show correct network icon for each insight
- Don't replace the colon in insight headlines
- Improve test coverage
Closes #1809
Don't link Facebook users to Twitter
Facebook plugin: correctly set/display auth error when there is one
Facebook plugin: match re-auth email copy to UI