MultiPanelPlot - Missing phase nrows & ncols

[jmbrewer]

In the MultiPanelPlot object init, self.phase_ncols and self.phase_nrows only defined if phase_ncols and phase_nrows are None. If you try to pass values and make a plot, it crashes when it cant find the properties. I added quick else statements to the constructor to define them and the plots themselves seem to work fine.