* src/io.c (io_final): No longer any need to reset stdio file
descriptors to blocking mode.
(write_raw_with_poll): Deleted function.
(io_set_type): Deleted function.
(io_init_fd): New argument, allowing certain fd:s to remain in
blocking mode.
(make_lsh_fd): New argument TYPE. Updated callers.
(close_fd): Don't close fd:s that are of type IO_STDIO.

Rev: src/io.c:1.209
Rev: src/io.h:1.108