Moved CubeGeometry to Three.Legacy.

src/Three.Legacy.js

@@ -3,6 +3,7 @@
  */
 
 Object.assign( THREE, {
+	CubeGeometry: THREE.BoxGeometry,
 	Face4: function ( a, b, c, d, normal, color, materialIndex ) {
 		console.warn( 'THREE.Face4 has been removed. A THREE.Face3 will be created instead.' );
 		return new THREE.Face3( a, b, c, normal, color, materialIndex );

src/extras/geometries/BoxGeometry.js

@@ -25,5 +25,3 @@ THREE.BoxGeometry = function ( width, height, depth, widthSegments, heightSegmen
 
 THREE.BoxGeometry.prototype = Object.create( THREE.Geometry.prototype );
 THREE.BoxGeometry.prototype.constructor = THREE.BoxGeometry;
-
-THREE.CubeGeometry = THREE.BoxGeometry;