Add special characters for creating the swing symbol

Musescore comes with a very nice Big Band template but is lacking the swing symbol (two eighth notes with beam and the quarter plus eighth triplet, may be the same for sixteenth swing), although I believe implementation could be very easy: Incorporate some new characters into the Musejazz font and make it available via "insert special characters". Adding a picture as proposed in some forum entries is not really the nice way to do it.