Updated the Distribution class so that getCurrentCenter and getCurrentCovar never return None.
Corrected bug with mpl.show so that it doesn't block execution. Modified the plot legend sa that each distribution is now displayed (not only classes), with its current prior probability. Modified the plotted ellipses so that the face color transparency is proportional to the current prior probability of the underlying distribution. Also added a dotted edge contour when the priors < 0.05.
Added read me file.