FreeBSD support for rvm

My secret project is mostly written in Ruby and I’ve recently been working on making sure it runs well using FreeBSD, as I experiment with that OS as the host.

I use rvm for managing my rubies as I hack away, but for some reason FreeBSD support is missing. I’ve added it in, based mainly on the OpenBSD support but with some specific FreeBSD variant differences.

It’s reasonably well tested for 2.0.0-p0 and 1.9.3-p194 MRI rubies on FreeBSD 8.3, 9.0 and 9.1 (all -RELEASE distributions), on both x86 and AMD64 processor architectures. Other rubies should work, at least if they do on OpenBSD they should on FreeBSD, but are untested.

The code is on my freebsd branch at github.