add example addressing Issue #1
add function to find the threshold ionization energy for a transition
refactoring
add functions to make log ticks and labels
removing unused code
doc update
fix typo in setup.py, thanks to Christoph Deil
Allow setting EBmV when calling extinction laws, add IRAC passbands, allow applying an extinction curve to an SED
bug fix
fix typos, add solar H/He/metal mass fractions from Asplund et al.
Add check to catch bad input
More info in README for Assef templates
remove trailing whitespace
allow reading CO transitions in findtrans
add function to read SDSS spectrum meta-data
update extinction docs
Allow Spectrum.read to parse SDSS fits spectra
Add more documentation
adding more tests
update doc url