correction for xterm terminal corruption.

under a standard xterm, emacs would randomly place status bar
text onto the screen while scrolling vertically. also, the
right side margin of the terminal would not be redrawn appropriately
while vertically scrolling.

it turns out that the OPOST termios output option ust be disabled
in the master pty before a new slave pty is spawned. i suspect that
postprocessing might be occurring twice in this odd situation
leading to the corruption.

to avoid yet another dependency to this project, a simple note was
made to the user: invoke stty -opost before executing index.js
in order to avoid xterm corruption.