make scaleFunction and rotationFunction type explicit

scaleFunction and rotationFunction were implicitly defined as any.
The TSC compiler ,flags these as error when compiling with option "-noImplicitAny"
I am trying to submit the babylon.d.ts file to definitelytyped site.
It rejects it due to these errors

src/Mesh/babylon.meshBuilder.ts

@@ -251,7 +251,7 @@
             return MeshBuilder._ExtrudeShapeGeneric(name, shape, path, scale, rotation, null, null, false, false, cap, false, scene, updatable, sideOrientation, instance);
         }
 
-        public static ExtrudeShapeCustom(name: string, options: { shape: Vector3[], path: Vector3[], scaleFunction?, rotationFunction?, ribbonCloseArray?: boolean, ribbonClosePath?: boolean, cap?: number, updatable?: boolean, sideOrientation?: number, instance?: Mesh }, scene: Scene): Mesh {
+        public static ExtrudeShapeCustom(name: string, options: { shape: Vector3[], path: Vector3[], scaleFunction?:any, rotationFunction?:any, ribbonCloseArray?: boolean, ribbonClosePath?: boolean, cap?: number, updatable?: boolean, sideOrientation?: number, instance?: Mesh }, scene: Scene): Mesh {
             var path = options.path;
             var shape = options.shape;
             var scaleFunction = options.scaleFunction || (() => { return 1; });