Fixed #21731 -- Made javascript_quote escapes '</'.
Fixed #17005 -- Added CurrentSiteMiddleware to set the current site on each request.

Thanks jordan at aace.org for the suggestion.
Fixed #17713 -- Renamed BaseDatabaseFeatures.allows_primary_key_0 to allows_auto_pk_0.

MySQL does allow primary key with value 0. It only forbids autoincrement
primary key with value 0.

Thanks Claude Paroz for the report.
Updated 1.6.2 release notes for release (and linkified tickets).
Bumped version number for 1.7a2