main.py: test run after mods to all other programs

- can now take either real or simulated data

- will plot CMD of the real/sim data.

- calculate likelihood for different alpha values.

- known issues:

  * likelihood code still has likelihood spikes towards the edges of
    the mass array.

  * likelihood rises with increasing power law alpha in both sim and
    real data w.o. bound, because there is no normalization to the
    number of stars per bin.

  * salpeter and chabrier modules may still have a very small
    magnitude shift in their luminosity functions relative to
    the dartmouth LF in the literature, because of how dN is
    calculated not at the center point of bins in dM, but at
    the left edge [have not checked this issue in a while]