hang on exit bug under Linux

[Markus Friedl]

for rlogin-like behaviour (i.e. a pty is allocated) it might
be an option to discard data, like telnetd/rlogind do.

for rsh-like behaviour data loss is not acceptable.


for example,

	$ rsh host broken-daemon

blocks too (on many platforms, if not, please show
me relevant rshd code). and it should block for ssh-1.2.32.