MacOS X Support

Support for Potato on MacOS X is planned for some point in the future. In theory, it should be working already, but the few people who've beta-tested it have reported problems (mostly bad performance issues) that I can't explain. (If you want to try, download the Starkit of Potato and run it with a MacOS X version of Tclkit 8.5) I don't have a Mac myself, so can't do anything to try and reproduce or debug the problem, so I've decided to put off supporting Mac OS until I can get my hands on one (which probably won't be any time soon). But, if anyone has about £550 GBP to spare to cover the cost of one, I would be happy to prioritize it ;)