Added function cdiDate_to_int64().

src/cdi_datetime.c

src/cdi_datetime.h

src/cgribexlib.c

src/grb_write.c

src/julian_date.c

src/stream_cdf_i.c

src/stream_ext.c

src/stream_gribapi.c

src/stream_record.c

src/stream_srv.c

src/taxis.c