fix an obscure crash reading from stream devices
-------------------- ChangeLog entries follow: --------------------
src/ChangeLog addition:
2010-01-27 Ben Wing <ben@xemacs.org>
* event-unixoid.c (read_event_from_tty_or_stream_desc):
Don't try to write one byte into a four-byte variable, leaving
the rest undefined. This is a recipe for crashing.