feat(params): additional fields and Result type

Now query params are handled completely, including clash check.
Additionally, there is a new result type which encapsulates everything.

It must be typed to the actual result type though, which can be a
request result

Author: Byron

gen/youtube3/src/cmn.rs

@@ -67,3 +67,17 @@ pub trait Delegate {
 pub struct DefaultDelegate;
 
 impl Delegate for DefaultDelegate {}
+
+
+/// A universal result type used as return for all action method results.
+pub enum Result {
+    /// The http connection failed
+    HttpError(hyper::HttpError),
+
+    /// An additional, free form field clashed with one of the built-in optional ones
+    FieldClash(&'static str),
+
+
+    /// It worked !
+    Success,
+}