new Qsend features in System 78

[Christopher C. Stacy <CStacy at MIT-AI>]

Sometimes, users may wish not to be interrupted with Qsends.  A new
function called CHAOS:QSENDS-OFF has been created for such occasions.
If you give it a string argument, the string will be returned to anyone
who tries to send to you.  Otherwise, they just get a note saying that
you are not accepting Qsends.  CHAOS:QSENDS-ON ungags you.

Also, CHAOS:SHOUT allows you to send a message to all Lisp Machines.

Chris