Squid Reverse Proxy Change redir domain(s) to use regex
Change the ACL for reverse proxy redirects from using the rather limited "dstdomain" to using "dstdom_rexex".
This makes the redirects much more flexible in general.
Also makes it possible to redirect a subdomain to a different mapping than the domain itself.
This is a more consistent approach as mappings and redirects are handled in a similar manner using regular expressions all the way.