Add simulate and verbose arguments

I pretty much couldn't imagine using Mackup without being able to test it first using this functionality, so I decided I'd try and write it!

I'm definitely a Python newbie so please be kind and let me know if I've done anything (or everything) horribly wrong :)

I had to do some research to avoid using globals and I copped the State class from here: http://stackoverflow.com/a/747888/771643.

I didn't think it made sense to pass args to the file operation commands. Doing so would fix the `args and args.simulate` verbosity (added to fix failing tests due to no State object) but I think I'd rather have verbosity there than on the calling side. Any suggestions on improving that are definitely welcome.