Edits to try to get 141125 to work with MPI

Still trying to get MPI working

Still more edits for MPI

Still more changes for MPI

This time to plot the plots from the saved chain

Still more changes

Ran out of colors in color array

More changes: added steps

Now it's working, so I added steps

More changes: run the right func

Run chain from where it left off

Fixed filename of pickled sampler

Got the right slice of the chain for restarting

Removed some extra whitespace
Fit all trajectories by least squares

Also, do background subtraction on both the Bid wells and the BH3 wells,
plot the averages, and plot the dose response of the fitted parameters.
Fit the resulting Fmax and k curves
Put fitting of k titration into own func