some more documentation updates and minor code cleanups.  Additionally True and true in the template are the same now, same for false/False and none/None.

--HG--
branch : trunk
diff --git a/tests/test_syntax.py b/tests/test_syntax.py
index 717e165..a126b5f 100644
--- a/tests/test_syntax.py
+++ b/tests/test_syntax.py
@@ -163,3 +163,11 @@
 def test_block_end_name(env):
     env.from_string('{% block foo %}...{% endblock foo %}')
     raises(TemplateSyntaxError, env.from_string, '{% block x %}{% endblock y %}')
+
+
+def test_contant_casing(env):
+    for const in True, False, None:
+        tmpl = env.from_string('{{ %s }}|{{ %s }}|{{ %s }}' % (
+            str(const), str(const).lower(), str(const).upper()
+        ))
+        assert tmpl.render() == '%s|%s|' % (const, const)