Make it clear that url-path is always case-sensitive.

Provide an example of using a regex to make it case-insensitive.
Make it clear that ScriptAlias is only used when you want
BOTH mapping and script-designation.

Partially in response to the disputed vulnerability:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-4110


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@432997 13f79535-47bb-0310-9956-ffa450edef68