Provide easy access to CoreMIDI for Ruby.

Please note that this is a work in progress. The code isn't tested and for all I know, 
it sets your house on fire, steals your car and runs over your dog and/or cat. So proceed 
with caution.

= Installation

  ruby extconf.rb
  make
  ruby coremidi.rb # Should exit with no errors

If installation fails:

  # Open rbcoremidi.xcodeproj in XCode and compile it
  cp build/Releases/rbcoremidi.bundle .
  /usr/bin/ruby coremidi.rb

Note that if installation fails, you can only use the Ruby built into Leopard (/usr/bin/ruby).