improved sandbox, added proper striptags and updated documentation to latest sphinx changes

--HG--
branch : trunk
diff --git a/jinja2/defaults.py b/jinja2/defaults.py
index 848cb8f..e124930 100644
--- a/jinja2/defaults.py
+++ b/jinja2/defaults.py
@@ -24,6 +24,7 @@
 
 DEFAULT_NAMESPACE = {
     'range':        xrange,
+    'dict':         lambda **kw: kw,
     'lipsum':       generate_lorem_ipsum
 }