OScope__EnableAnnotation (ul_pbar_graphics)

 *  Synopsis:
 *    #include <ul_pbar_graphics:oscope.h>
 *
 *    TOScope__Result OScope__EnableAnnotation( 
 *                    EAnnotationOrientation theOrientation, int characters )
 *
 *  Function intent:
 *    OScope__EnableAnnotation() allows the user to request the creation of an
 *    "annotation" window to be added to the oscilloscope display.  The
 *    annotation window may be oriented horizontally accross the bottom of the
 *   display, or vertically along the right hand side of the display.
 *  Function parameters:
 *    EAnnotationOrientation    theOrientation  orientation request:
 *                                                      kAnnotationHorizontal
 *                                                      kAnnotationVertical
 *    int                       characters      window width/height in characters
 *  Function return value:
 *    CBS_OK    success
 *    ~CBS_OK           OScope__DisplayScreen() already called...
 *                      or OScope__EnableAnnotation() has already been called
 *    CBS_INVTYP        illegal orientation request
 *    CBS_INVSIZ        characters request to large to properly display
 *    else              wn_xxx() function error occured