Reviewed-by: Brian Behlendorf, Mark Cox, Chuck Murcko

Allow options to be set/unset individually, rather than replacing existing
options settings. Used as: "Options +Indexes -Multiviews", etc.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@76964 13f79535-47bb-0310-9956-ffa450edef68