Rewrite test scripts in the configure-like portable way.

tests/pio_cksum_asynch.in

tests/pio_cksum_cdf.in

tests/pio_cksum_fpguard.in

tests/pio_cksum_grb2.in

tests/pio_cksum_mpi_fw_at_all.in

tests/pio_cksum_mpi_fw_at_reblock.in

tests/pio_cksum_mpi_fw_ordered.in

tests/pio_cksum_mpinonb.in

tests/pio_cksum_writer.in

tests/pio_write_deco2d_run.in

tests/pio_write_run.in

tests/test_byteswap_run.in

tests/test_cdf_const.in

tests/test_cdf_transformation.in

tests/test_chunk_cksum.in

tests/test_cksum_base

tests/test_cksum_extra.in

tests/test_cksum_grib.in

tests/test_cksum_grib2.in

tests/test_cksum_ieg.in