Get rid of bash for dartdoc and do the whole thing in dart.

lib/dartdoc/utils.dart

Index: lib/dartdoc/utils.dart
diff --git a/lib/dartdoc/utils.dart b/lib/dartdoc/utils.dart
index 576f3c55b31bc32fa1eadf91df0784eb639e7f64..b8f7fbda5eddb256e9889166217c1f0d80f55652 100644
--- a/lib/dartdoc/utils.dart
+++ b/lib/dartdoc/utils.dart
@@ -4,15 +4,6 @@
 
 // Generic utility functions.
 
-/** Invokes [callback] and returns how long it took to execute in ms. */
-num time(callback()) {
-  final watch = new Stopwatch();
-  watch.start();
-  callback();
-  watch.stop();
-  return watch.elapsedInMs();
-}
-
 /** Turns [name] into something that's safe to use as a file name. */
 String sanitize(String name) => name.replaceAll(':', '_').replaceAll('/', '_');