update comments

src/utils.js

@@ -27,27 +27,6 @@ function deepModify ( source, target ) {
     return target;
 }
 
-// This is an old clone implementation which is
-// pretty slow. It will be replaced by a JSON parsing
-// which is essentially faster than this implementation
-// below.
-//
-// function clone ( object ) {
-// 	if ( !object )
-// 		return object;
-//     if ( Array.isArray( object ) )
-//         return [ ...object ].map( e => clone( e ) );
-//     if ( typeof object !== "object" )
-//         return object;
-// 	return Object.fromEntries(
-// 		Object.entries( object ).map(
-//             ( [ key, value ] ) => [ key, clone( value ) ]
-//         )
-// 	);
-// }
-//
-// Node.js... What is wrong with you :sob:
-
 function clone(obj) {
     var ret = {}, key, val;
     for ( key in obj ) {