Add a script to generate HTML and DOM docs with cross-links to one another.

frog/library.dart

 // Copyright (c) 2011, 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.
 
 class LibraryImport {
   String prefix;
   Library library;
   LibraryImport(this.library, [this.prefix = null]);
 }
 
@@ skipping 265 matching lines @@
       type.resolve();
     }
   }
 
   visitSources() {
     var visitor = new _LibraryVisitor(this);
     visitor.addSource(baseSource);
   }
 
   toString() => baseSource.filename;
+
+  int hashCode() => baseSource.filename.hashCode();
+
+  bool operator ==(other) => other is Library &&
+    other.baseSource.filename == baseSource.filename;
 }
 
 
 class _LibraryVisitor implements TreeVisitor {
   final Library library;
   DefinedType currentType;
   List<SourceFile> sources;
 
   bool seenImport = false;
   bool seenSource = false;
@@ skipping 184 matching lines @@
 
   void visitFunctionDefinition(FunctionDefinition node) {
     currentType.addMethod(node.name.name, node);
   }
 
   void visitFunctionTypeDefinition(FunctionTypeDefinition node) {
     var type = library.addType(node.func.name.name, node, false);
     type.addMethod(':call', node.func);
   }
 }