Use raw SQL in MemberDistance calculations

Results in around a 50% decrease in
the rake application:cache:member_distances
https://github.com/openaustralia/publicwhip/issues/602
Move logout link into dropdown menu
Move editing of profile from user page to dropdown. Fixes #583
Remove text about cookies and stuff
Sign up link exists on login page so remove from nav
Make order of results deterministic
Add GA to bottom of page. Fixes #565
Extract partial