add leslie Mapper

This MR adds a mapper plugin to make the dodecahedronLeslie spatializer work. Example use:

(
~config = SatieConfiguration(s, listeningFormat: [\dodecahedronLeslie], outBusIndex: [0]);
~satie = Satie.new(~config);
~satie.waitForBoot({
	~satie.makeSynthDef(\defaultLeslie, \default, [],[],[],~config.listeningFormat, paramsMapper: \leslieMapper);
	z = ~satie.makeInstance(\boo, \defaultLeslie);
	s.sync;
	s.plotTree;
	s.meter;
	s.makeGui;
})
)


z.set(\gainDB, -20);  // set gain
z.set(\rotationSpeed, 0.1); // change rotation speed