I'm wrapping a library with swig, and I'd like to also implement some
rubyisms for it in a regular ruby file. So I have:

ext/sndfile/extconf.rb
ext/sndfile/sndfile.i
ext/sndfile/sndfile.h
lib/sndfile.rb

I'd like to have lib/sndfile.rb require the shared library. In the past
I've done this with require 'foo.so', which worked great on linux but it
occurs to me that it's not very cross-platform. (On my iBook for example
the output is sndfile.bundle)

Is there an elegant way to require the shared library and not the ruby
lib? Or do I just need to name my shared library something else? (or
vice versa) I'd like people to just be able to do 

  require 'sndfile'