doc: General improvements.

recipe_engine/loader.py

Index: recipe_engine/loader.py
diff --git a/recipe_engine/loader.py b/recipe_engine/loader.py
index 759447046e7b15fa3c704a3a17e35082c1e36e8b..d570bd5304446429f51fba4ed1a30d3951427d1f 100644
--- a/recipe_engine/loader.py
+++ b/recipe_engine/loader.py
@@ -1,4 +1,4 @@
-# Copyright 2013-2015 The Chromium Authors. All rights reserved.
+# Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
@@ -259,6 +259,15 @@ class UniverseView(collections.namedtuple('UniverseView', 'universe package')):
         module_name = os.path.dirname(recipe)[len(path)+1:]
         yield recipe, '%s:example' % module_name
 
+  def loop_over_recipe_modules(self):
+    """Yields the paths to all the modules that this view can see."""
+    for path in self.package.module_dirs:
+      if os.path.isdir(path):
+        for item in os.listdir(path):
+          subpath = os.path.join(path, item)
+          if _is_recipe_module_dir(subpath):
+            yield os.path.basename(subpath)
+
 
 def _amend_exception(e, amendment):
   """Re-raise an exception e, appending amendment to the end of the message."""