fix(delegate): it now works in every which way

Custom property annotations have been very useful, to steer very special
cases.

It's also good that now there is enough infrastructure to deal with
any amount of additional type parameters.

Author: Byron

gen/youtube3/src/cmn.rs

@@ -2,7 +2,6 @@
 // DO NOT EDIT
 use std::marker::MarkerTrait;
 use std::io::{Read, Seek};
-use std::borrow::BorrowMut;
 
 use oauth2;
 use hyper;
@@ -54,7 +53,7 @@ struct JsonServerError {
 ///
 /// It contains methods to deal with all common issues, as well with the ones related to 
 /// uploading media
-pub trait Delegate: Clone {
+pub trait Delegate {
 
     /// Called whenever there is an HttpError, usually if there are network problems.
     /// 
@@ -63,3 +62,8 @@ pub trait Delegate: Clone {
         oauth2::Retry::Abort
     }
 }
+
+#[derive(Default)]
+pub struct DefaultDelegate;
+
+impl Delegate for DefaultDelegate {}