refactor: Be consistent in adding methods last

This will unblock us from removing the `version` hack because we'll
always get the right precedence.

Later we can explore ways of moving the app methods to being done first.
The big problem is with `#[clap(subcommand)]` because we need to call
those app methods on the subcommands `App` *and* override them with app
methods on the variant, requiring the app methods to be last to get
precedence.

clap_derive/src/derives/args.rs

@@ -353,8 +353,8 @@ pub fn gen_augment(
     let version = parent_attribute.version();
     quote! {{
         #( #args )*
-        let #app_var = #app_var#app_methods;
         #subcmd
+        let #app_var = #app_var#app_methods;
         #app_var#version
     }}
 }

clap_derive/src/derives/subcommand.rs

@@ -274,8 +274,8 @@ fn gen_augment(
     let app_methods = parent_attribute.top_level_methods();
     let version = parent_attribute.version();
     quote! {
-            let app = app #app_methods;
             #( #subcommands )*;
+            let app = app #app_methods;
             app #version
     }
 }