The window that appears when the program first comes up 
is divided into three sections:
 - The top line containing a menu bar and various toggle buttons,
 - a graphical process tree display area in the middle,
 - status information on the bottom.

There is a separate help describing toggle buttons; pop up menus
have their own context-specific help when they pop up.

Status information at the bottom contains the load average for the
last minute, 5 and 15 minutes respectively.  After this is a count of
the processes shown.  On another line is the version number and
refresh rate.
