find an open port in a more robust way

contrib/ruby/jasmine_runner.rb

@@ -2,7 +2,7 @@ require 'socket'
 require 'erb'
 
 module Jasmine
-  # this seemingly-over-complex method is necessary to get it to work on at least some machines
+  # this seemingly-over-complex method is necessary to get an open port on at least some of our Macs
   def self.open_socket_on_unused_port
     infos = Socket::getaddrinfo("localhost", nil, Socket::AF_UNSPEC, Socket::SOCK_STREAM, 0, Socket::AI_PASSIVE)
     families = Hash[*infos.collect { |af, *_| af }.uniq.zip([]).flatten]