88/05/24 - WZ - ping2mat.c
                updated to include navigation data
89/05/24 - WZ - ping2mat.c
                updated for CODAS3 linking
89/09/05 - JR - ping2mat.c
                removed path of ADCP.H because of
                reorganization of subdirectories
90/06/29 - JR - *.c
                replaced <stdlib.h> with "common.h"
91/05/15 - WZ - ping2mat.c
                1. changed variable names of NAVIGATION_TYPE to
                   coincide with that in ADCP.H
                2. modified the program so that it can handle the
                   case when profiles with different bin numbers
                   within a time range user specified.
91/09/05 - JR - ping2mat.c
                modified to remove restriction on no. of profiles
                that could be retrieved at a time (because of unsigned
                int arg to calloc())
93/08/12 - JR - ping2mat.c
                modified to also retrieve error velocity (E) if
		available and requested
95/04/13 - JR - ping2mat.c:
		fixed usage message to reflect proper syntax in
		giving time range argument:  a hyphen, not a
		comma, should be used to link the date and time.
