Make dart:dom implementation types private so they don't muddle the docs.

client/dom/generated/src/frog/HTMLScriptElement.dart

 
-class HTMLScriptElementJs extends HTMLElementJs implements HTMLScriptElement native "*HTMLScriptElement" {
+class _HTMLScriptElementJs extends _HTMLElementJs implements HTMLScriptElement native "*HTMLScriptElement" {
 
   bool get async() native "return this.async;";
 
   void set async(bool value) native "this.async = value;";
 
   String get charset() native "return this.charset;";
 
   void set charset(String value) native "this.charset = value;";
 
   bool get defer() native "return this.defer;";
@@ skipping 13 matching lines @@
   void set src(String value) native "this.src = value;";
 
   String get text() native "return this.text;";
 
   void set text(String value) native "this.text = value;";
 
   String get type() native "return this.type;";
 
   void set type(String value) native "this.type = value;";
 }