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

utils/dartdoc/files.dart

Index: utils/dartdoc/files.dart
diff --git a/utils/dartdoc/files.dart b/utils/dartdoc/files.dart
index a75744c17756468091ea226355ee3711d671a64c..5352a9271b230a0af9144a9fbf8a38ccf0445c0f 100644
--- a/utils/dartdoc/files.dart
+++ b/utils/dartdoc/files.dart
@@ -10,8 +10,6 @@ String _filePath;
 /** The file currently being written to. */
 StringBuffer _file;
 
-FileSystem files;
-
 startFile(String path) {
   _filePath = path;
   _file = new StringBuffer();
@@ -28,7 +26,7 @@ writeln(String s) {
 
 endFile() {
   String outPath = '$outdir/$_filePath';
-  files.createDirectory(dirname(outPath), recursive: true);
+  world.files.createDirectory(dirname(outPath), recursive: true);
 
   world.files.writeString(outPath, _file.toString());
   _filePath = null;