#39 UPnP - Adding Port Forward

[yarrt]

UPnP might allow ArmagetronAd to automatically allocate
add a portforwarding to a router. This shouldn't be a
security issue. Mac OS X support is still missing in
the following library, but it has linux and windows
support in trunk.

http://www.libupnp.org/svn/index.cgi/libupnp/view/trunk/ChangeLog