. . .   MOUSE SYSTEM OVERVIEW   . . .
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 The MOUSE SYSTEM provides a graphic mouse while in text mode (EGA or VGA
 required).  All of the required functions are provided to query the mouse for
 location and status.  Implementation of the MOUSE SYSTEM is provided through
 the EVENT SYSTEM.

 When on the mouse can be toggled between a pointer and an hour glass.

 The mouse is intelligent and will re-display itself if it is OVERWRITTEN as
 in the situation where the mouse is placed over a time display which is
 written to the screen every second.  Because the characters in the immediate
 area of the mouse cursor location are readdressed to different ASCII values,
 if the screen is scrolled, not overwritten, the screen and mouse would
 become out of sync.  To prevent this, every time a scroll process is about to
 be conducted the mouse is to be turned off and then on again after the scroll
 process has completed.  When doing a SAVESCREEN() the mouse should be turned
 off and then on again.  ShadowBox() does it automatically.

 Notes:

 The stabilize() method from TBROWSE performs a scroll therefore the
 mouse should be turned off prior to a stabilize().

 When the CA-Clipper function SETMODE() is called a call to ResetMouse()
 must be made directly afterward.  This is to ensure the mouse is in sync
 with the current screen mode.