Patch by Xavier de Gaye.

The update_idletasks solution was provided by Serhiy Storchaka.

BrokenPipeError when the child process dies before .communicate()
is called in more (all?) circumstances.

Patch by Sean Rodman, test by Kaushik N.

Patch contributed by Dave Sawyer.

Patch contributed by Dave Sawyer.

[merge from 3.5] - issue8519 - Reference termios and ioctl manual pages in the library documentation.

error message as some numbers map to multiple names.

when the child process died due to a signal.

lacking os.fork().

signal number when the process died due to a signal.

as Windows that do not support os.fork().