fixed most warnings

examples/pio/collectData.c

src/cdi.h

src/cdi_int.c

src/cdi_int.h

src/cdi_util.c

src/extralib.c

src/file.c

src/gaussgrid.c

src/ieglib.c

src/model.c

src/servicelib.c

src/stream_cdf.c

src/stream_gribapi.c

src/table.h

src/zaxis.c

tests/cksum_read.c

tests/cksum_write.c