Make sure mod_rewrite matches URL schemes case-insensitive and also allow

additional (commonly used) URL schemes ldap:, news: and mailto:.

Requested by: Klaus Johannes Rusch <KlausRusch@atmedia.net>
Submitted by: Ralf S. Engelschall
Reviewed by: Ralf S. Engelschall
PR: 3140


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@84046 13f79535-47bb-0310-9956-ffa450edef68