Add WCSlib, a library for handling World Coordinate System transformations in astronomy.

WCSlib is the authoritative library for doing these transformations
(eg: if a star is at this position in the sky and my telescope is
pointed like so, at which pixel coordinate will the star appear?), and
is pretty widely used in astronomical code.
Merge branch 'wcslib-4.14'
First shot at adding an Astrometry.net formula
Add "debug"; set environment
update to today's release; add NETPBM environment variables
fix 'brew audit' complaints
make extras and py optional
Add WCStools-3.8.6: library and utilities for astronomical World Coordinate Systems transformations.
Clean up and comment
Merge branch 'wcstools-3.8.6-b'
Add ATLAS and SExtractor formulas
cleanup
add TMV-CPP library
Add gal-sim formula
fix 'brew audit' complaints; add note about PYTHONPATH
meh
uprev to v 0.2; replace python dir by python2.7
New wcslib release (old one disappeared)
Add formula for ATLAS

The formula is based on one at camphogg/homebrew-science and on one I developed independently.
Add formula for sextractor.

Based on one I developed locally and on camphogg/homebrew-science.