Moved most of html lib generating scripts into tools.

tools/dom/templates/html/impl/impl_IDBFactory.darttemplate

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of $LIBRARYNAME;
 
 /// @domName $DOMNAME$ANNOTATIONS
 class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
   /**
    * Checks to see if Indexed DB is supported on the current platform.
    */
   static bool get supported {
 $if DARTIUM
     return true;
 $else
     return JS('bool',
         '!!(window.indexedDB || '
         'window.webkitIndexedDB || '
         'window.mozIndexedDB)');
 $endif
   }
 
 $!MEMBERS
 }