Smoke for Mac

From Steve Dekorte:

An OSX screensaver port of Gustav Taxen's(gustavt@nada.kth.se) Smoke demo with more controls and a few small changes. This program uses the fluid dynamics solver presented in Jos Stam, "A Simple Fluid Solver Based on the FFT", (http://www.dgp.utoronto.ca/people/stam/reality/Research/pub.html) to produce a impression of swirly smoke in real-time. This implementation uses the "The Fastest Forurier Transform in the West" library (http://www.fftw.org).