Adds makefiles for Mac OSX using homebrew for dependencies

Not sure if you need it, but i used it in my macbook and it works. The only extra instruction is to add some symbolic links to some of the libraries in /usr/local/Cellar/fftw/3.3.4/lib from libfftw3.* to libfftw.
All dependencies were downloaded with homebrew 

```bash
brew install gcc46
brew install openmpi
brew install fftw
```