Concentrate all PIO test logic in 'pio_write_run.in' (again).

tests/pio_cksum_asynch.test.in

tests/pio_cksum_fpguard.test.in

tests/pio_cksum_grb2.test.in

tests/pio_cksum_mpi_fw_at_all.test.in

tests/pio_cksum_mpi_fw_at_reblock.test.in

tests/pio_cksum_mpi_fw_ordered.test.in

tests/pio_cksum_mpinonb.test.in

tests/pio_cksum_nc.test.in

tests/pio_cksum_nc2.test.in

tests/pio_cksum_nc4.test.in

tests/pio_cksum_writer.test.in

tests/pio_write_deco2d_run.in

tests/pio_write_deco2d_run_parallel.test.in

tests/pio_write_dist_array.test.in

tests/pio_write_run.in

tests/pio_write_run_parallel.test.in