Some maintenance; tests now run and pass with Ruby 1.9.3/Inform 6.31

[mattkimmel]

I did some work to get dorothy running and all tests passing again. I fixed some tests that weren't working properly under Inform 6.31; I added some marshaling code to memory.c so the state of the machine could be Marshaled again as per the tests; and I re-introduced an output method to Z::Machine so the bin script would work and the interface would match the README. Hope you find this helpful! I think dorothy is a great project and am looking forward to using it for a project I have in mind.