setup the directories to use for multiplier parameterization.  Directories
        are make within the PstFromFlopyModel.m.model_ws directory

def setup_mult_dirs(self):
        """ setup the directories to use for multiplier parameterization.  Directories
        are make within the PstFromFlopyModel.m.model_ws directory

        """
        # setup dirs to hold the original and multiplier model input quantities
        set_dirs = []
#        if len(self.pp_props) > 0 or len(self.zone_props) > 0 or \
#                        len(self.grid_props) > 0:
        if self.pp_props is not None or \
                        self.zone_props is not None or \
                        self.grid_props is not None or\
                        self.const_props is not None or \
                        self.kl_props is not None:
            set_dirs.append(self.arr_org)
            set_dirs.append(self.arr_mlt)
 #       if len(self.bc_props) > 0:
        if len(self.temporal_list_props) > 0 or len(self.spatial_list_props) > 0:
            set_dirs.append(self.list_org)
        if len(self.spatial_list_props):
            set_dirs.append(self.list_mlt)

        for d in set_dirs:
            d = os.path.join(self.m.model_ws,d)
            self.log("setting up '{0}' dir".format(d))
            if os.path.exists(d):
                if self.remove_existing:
                    shutil.rmtree(d,onerror=remove_readonly)
                else:
                    raise Exception("dir '{0}' already exists".
                                    format(d))
            os.mkdir(d)
            self.log("setting up '{0}' dir".format(d))