Get dartdoc in the SDK and working correctly.

lib/dartdoc/dartdoc.dart

Index: lib/dartdoc/dartdoc.dart
diff --git a/utils/dartdoc/dartdoc.dart b/lib/dartdoc/dartdoc.dart
similarity index 99%
rename from utils/dartdoc/dartdoc.dart
rename to lib/dartdoc/dartdoc.dart
index 417234949756f9bc645b8045a65965ef773379be..9b7496b78a8e19159b92b8bc44323e04fc41a0ae 100644
--- a/utils/dartdoc/dartdoc.dart
+++ b/lib/dartdoc/dartdoc.dart
@@ -51,7 +51,7 @@ final MODE_STATIC = 0;
 final MODE_LIVE_NAV = 1;
 
 /**
- * Run this from the `utils/dartdoc` directory.
+ * Run this from the `lib/dartdoc` directory.
  */
 void main() {
   final args = new Options().arguments;
@@ -84,6 +84,9 @@ void main() {
   }
 
   final files = new VMFileSystem();
+  // TODO(rnystrom): Note that the following line gets munged by create-sdk to
+  // work with the SDK's different file layout. If you change it here, make
+  // sure SDK builds still work.
   parseOptions('../../frog', ['', '', '--libdir=../../frog/lib'], files);
   initializeWorld(files);