galfit 3.0.5: new formula

Adds `galfit` 3.0.5 from http://users.obs.carnegiescience.edu/peng/work/galfit/galfit.html.

Unfortunately, due to licensing problems, there are only binaries available for the time being. I'm not sure if that makes galfit ineligible for homebrew-science.

Should be `== :mavericks` unless it supports 10.10