utf8_off session_data for DBs that return utf8
Use UNION ALL in history queries
Do not order checkers by message
Remove useless indexes on bugs_activity, fix count(*) from attach_data
Fix bug form when no keywords are available
Uppercase BIGINT
Fix Oracle DB driver (basic operations now work again)
Oracle DB driver code style
Update Bugzilla Guide up to the installation of web server
Fix config option parsing in HTTPServerSimple.pl
Update webserver configuration docs
Fix negative number rounding
SQLite support, including EXPLAIN and FTS4 fulltext search
Make contrib/bzdbcopy.pl actually work with anything other than Pg,
independent of current localconfig.

Never use Bugzilla->dbh in Bugzilla::DB::Schema, store and use $self->{dbh} instead.
Replace LEFT JOIN with INNER JOIN whenever it's possible

This only has profit for SQLite; no profit for normal databases.