[libvirt] gem install ruby-libvirt fails on FreeBSD 10.2

Hi, Installing the ruby-libvirt gem fails on FreeBSD 10.2 since it can't locate the lib and include dir. Installing with: gem install ruby-libvirt -- --with-libvirt-include=/usr/local/include/libvirt --with-libvirt-lib=/usr/local/lib/libvirt.so works fine. It would be great if this worked out of the box, e.g. detects that it is building on BSD and applies the above settings as default, or at least it could be provided as a hint if running make fails to guide ruby noobs, like me. Regards, Rickard von Essen