Drafting Spitzer instruments.
Working on spitzer.IRAC.ccorrection.
More Spitzer IRAC color correction work, including tests.
Finished IRAC color corrections.

Agrees with IRAC Instrument Handbook to 1% for the most part.
Merge pull request #16 from mkelley/efrho

Make AfrhoThermal effectively use efrho, rather than Afrho.
Merge pull request #17 from mkelley/spitzer

New instruments.spitzer with IRAC.
Merge branch 'master' into dev