Add constructors for SVG elements and remove static factory providers for html elements.

sdk/lib/html/templates/html/impl/factoryprovider_SvgElements.darttemplate

Index: sdk/lib/html/templates/html/impl/factoryprovider_SvgElements.darttemplate
===================================================================
--- sdk/lib/html/templates/html/impl/factoryprovider_SvgElements.darttemplate	(revision 0)
+++ sdk/lib/html/templates/html/impl/factoryprovider_SvgElements.darttemplate	(working copy)
@@ -0,0 +1,8 @@
+// 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 svg;
+
+class _SvgElements {
+$!FACTORY_METHODS}