Started to work on Python 3 support.

--HG--
branch : trunk
diff --git a/jinja2/lexer.py b/jinja2/lexer.py
index 919cba8..335e9ca 100644
--- a/jinja2/lexer.py
+++ b/jinja2/lexer.py
@@ -253,10 +253,9 @@
         return TokenStreamIterator(self)
 
     def __nonzero__(self):
-        """Are we at the end of the stream?"""
         return bool(self._pushed) or self.current.type is not TOKEN_EOF
 
-    eos = property(lambda x: not x.__nonzero__(), doc=__nonzero__.__doc__)
+    eos = property(lambda x: not x, doc="Are we at the end of the stream?")
 
     def push(self, token):
         """Push a token back to the stream."""