Negotiation changes: Don't output empty content-type in variant list;

Output charset in variant list; Return sooner from handle_multi() if
no variants found; Add handling of '*' wildcard in Accept-Charset.

Submitted by: Petr Lampa and Paul Sutton
Reviewed by: Roy Fielding, Jim Jagielski


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@77722 13f79535-47bb-0310-9956-ffa450edef68