Add count of undefined soil/land/dem cases to "copy_into_attributes" files

[wknoben]

E.g.

    # Print water counts
    if is_water > 0:
        print('HRU identified as exclusively water in {} cases. Note that SUMMA skips hydrologic calculations for such HRUs.'.format(is_water))
    # Print undefined counts
    if is_undefined > 0:
        print('Unable to identify HRU land class in {} cases. HRU value filled with -999 which will lead to SUMMA error'.format(is_undefined))

[wknoben]

Relates to #87