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

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

 
-class HTMLDocumentJs extends DocumentJs implements HTMLDocument native "*HTMLDocument" {
+class _HTMLDocumentJs extends _DocumentJs implements HTMLDocument native "*HTMLDocument" {
 
-  ElementJs get activeElement() native "return this.activeElement;";
+  _ElementJs get activeElement() native "return this.activeElement;";
 
   String get alinkColor() native "return this.alinkColor;";
 
   void set alinkColor(String value) native "this.alinkColor = value;";
 
-  HTMLAllCollectionJs get all() native "return this.all;";
+  _HTMLAllCollectionJs get all() native "return this.all;";
 
-  void set all(HTMLAllCollectionJs value) native "this.all = value;";
+  void set all(_HTMLAllCollectionJs value) native "this.all = value;";
 
   String get bgColor() native "return this.bgColor;";
 
   void set bgColor(String value) native "this.bgColor = value;";
 
   String get compatMode() native "return this.compatMode;";
 
   String get designMode() native "return this.designMode;";
 
   void set designMode(String value) native "this.designMode = value;";
 
   String get dir() native "return this.dir;";
 
   void set dir(String value) native "this.dir = value;";
 
-  HTMLCollectionJs get embeds() native "return this.embeds;";
+  _HTMLCollectionJs get embeds() native "return this.embeds;";
 
   String get fgColor() native "return this.fgColor;";
 
   void set fgColor(String value) native "this.fgColor = value;";
 
   String get linkColor() native "return this.linkColor;";
 
   void set linkColor(String value) native "this.linkColor = value;";
 
-  HTMLCollectionJs get plugins() native "return this.plugins;";
+  _HTMLCollectionJs get plugins() native "return this.plugins;";
 
-  HTMLCollectionJs get scripts() native "return this.scripts;";
+  _HTMLCollectionJs get scripts() native "return this.scripts;";
 
   String get vlinkColor() native "return this.vlinkColor;";
 
   void set vlinkColor(String value) native "this.vlinkColor = value;";
 
   void captureEvents() native;
 
   void clear() native;
 
   void close() native;
 
   bool hasFocus() native;
 
   void open() native;
 
   void releaseEvents() native;
 
   void write(String text) native;
 
   void writeln(String text) native;
 }