telnet-probe: fix byte-by-byte copying
telnet-probe: fix byte-by-byte copying

During the transition to the NSS libraries, a __pmWrite call replaced
a fputc when transcribing bytes to/from the remote socket.  This was
broken because the parameter to __pmWrite was an int rather than a
char, and so instead of sending 'a', telnet-probe sends 'a\0\0\0'.
Similarly on the socket-receive side, we tried to read ints rather than
chars via __pmRead.  We now narrow the int-carrying values to chars
where they belong.

prasincs/pcp,aeg-aeg/pcpfans,adfernandes/pcp,tjanez/pcp,prasincs/pcp,wuliming/pcp,wuliming/pcp,prasincs/pcp,mbaldessari/pcp,wuliming/pcp,aeg-aeg/pcpfans,adfernandes/pcp,tjanez/pcp,prasincs/pcp,tjanez/pcp,edwardt/pcp,mbaldessari/pcp,andyvand/cygpcpfans,andyvand/cygpcpfans,mbaldessari/pcp,andyvand/cygpcpfans,prasincs/pcp,adfernandes/pcp,edwardt/pcp,tjanez/pcp,mbaldessari/pcp,mbaldessari/pcp,tjanez/pcp,tjanez/pcp,adfernandes/pcp,adfernandes/pcp,aeg-aeg/pcpfans,andyvand/cygpcpfans,wuliming/pcp,wuliming/pcp,wuliming/pcp,adfernandes/pcp,prasincs/pcp,adfernandes/pcp,adfernandes/pcp,edwardt/pcp,edwardt/pcp,aeg-aeg/pcpfans,edwardt/pcp,wuliming/pcp,andyvand/cygpcpfans,wuliming/pcp,prasincs/pcp,aeg-aeg/pcpfans,mbaldessari/pcp,tjanez/pcp,prasincs/pcp,edwardt/pcp,aeg-aeg/pcpfans,tjanez/pcp,edwardt/pcp,andyvand/cygpcpfans,aeg-aeg/pcpfans,edwardt/pcp,andyvand/cygpcpfans,andyvand/cygpcpfans,aeg-aeg/pcpfans