Re-committing fisher_forecast.py.  I initialized the repo with the wrong version.
This one does a matrix operation to calculate the Fisher matrix instead of a slow
summing operation to define each element of the Fisher matrix.
Made minor changes to the default legend positions for each plot.
A new script to plot several sets of bandpowers.
Calculated several sets of bandpower realizations (100 per set) for various
sky coverage and map depth settings, as defined in the filenames.
Added the new function get_cov_matrix, but it's not working yet.
Small change to plot_spectra.py to add a call to get_cov_matrix.
Saved some comments in function get_cov_matrix so I know where I left off.
Adding cov matrix conditioning function.