Lots of changes:

1. Instituted cross checking with Draine maps for low AV when
selecting foreground CMD model (isolatelowAV.py).

2. Fixed up a few bugs in isolatelowAV.py -- handle zero noise case
and add on inner galaxy lgnstar maximum properly

3. Lots of code in analysis.py to compare to draine plots.

4. Adjusted prior to be log normal in x, and moved default center to
much lower f_red. Also dropped default number of points in unreddened
model, to deal with lower number of stars in unreddened CMD after
instituting draine low-AV condition.