This is yet another mail watcher.  This one combines the features of xbiff
and InterViews' mailbox: it has an active icon which changes state to
indicate the arrival of new mail, while the main window displays the senders
and subjects of the (new) messages in the user's maildrop.  It understands
both MMDF and sendmail-style maildrops.  It works with X11R5 and X11R4 (with
the enclosed minor patch to Xaw/Label.c applied), and with *twm and mwm.
