Merge pull request #923 from buttscicles/readme-contents-fix

Fix broken link in README contents list
Redirect communities to slug; #926
Show empty communities instead of 404; #909
Bump version to 8.2.6
Bump version to 8.2.6-dev
Move communities.json under for/

This way we don't have to set the username in a cookie. Should've done
this before.
Stop setting username in cookie

Previous commit removed the need for this. This goes back to what it was
before we changed it. However, ; is still not allowed in usernames, just
in case we want to come back to this later.
Bump version to 8.2.7
Bump version to 8.2.7-dev
Add community listing to public profiles; #928
Tweak padding on communities list
Tune communities.json for anon access
Start a communities listing page; #911
Bump version to 8.2.8
Bump version to 8.2.8-dev
Evolve community listing; #911

This puts a listing grouped by viability (per NMEMBERS_THRESHOLD) in the
main page and a total communities count in the box.
Bump version to 8.2.9
Bump version to 8.2.9-dev
Bump version to 8.2.10
Bump version to 8.2.10-dev