draw-bitmap-section-smooth in bitmap-dc%

Display part of a bitmap with smooth scaling. For most platforms, this method produces better results than adjusting the scale of a drawing context before using draw-bitmap and draw-bitmap-section, but this method is much slower.

• (send a-bitmap-dc draw-bitmap-section-smooth source dest-x dest-y dest-width dest-height src-x src-y src-width src-height mask) -> boolean
     source : bitmap% object
     dest-x : real number
     dest-y : real number
     dest-width : non-negative real number
     dest-height : non-negative real number
     src-x : real number
     src-y : real number
     src-width : non-negative real number
     src-height : non-negative real number
     mask : bitmap% object or #f