net-analyzer/rrdtool is installing itself into /opt. I _think_ libgd needs some updates as well in concert with this, also possibly an update to libpng. been a while since i investigated, this is going from memory. creating a report so i dont forget :)
FIxed, now installs to /usr/share/rrdtool
I made some further fixes to this. The binaries needed to be in /usr/bin, and there were some optional perl and tcl things that needed to be done. Also, the manpages and documentation in the packages Makefile completely ignore mandir, so that was fixed as well.