patch-dns-hosts-support

- added support for a temporary overwrite of the hosts entry for the baseurl, allowing checking of vhosts behind proxies and realservers behind loadbalancers.
- uses module LWP::UserAgent::DNS::Hosts to change the ip of the target url.
- uses module URI to extract fqdn needed for LWP::UserAgent::DNS::Hosts
- use <realserverip>x.x.x.x</realserverip> in the config.xml to overwrite the dns to target e.g. 127.0.0.1 or the ip of your realserver