Modified coefficient calculation and Q matrix calculation in sph_harm_coeffs.py so that only specified baselines will enter the calculation (instead of all of the baselines for an array). Also added a function that returns a specified number of the smallest baselines for a given array. Added to the info_matrix function plots for the eigenvalues, eigenvectors, and first row. Added a function to calculate a window function for an M specified within the function and to plot the first row of the W matrix.

In useful_functions.py I modified the general_lstsq_fit_with_err() function so that it has the option of using a pseudo inverse in the calculation.