Improved test invokation. Picks up doctests within Jinja now, changed
doctests that just show usage that would not work on their own so that
they are standard code blocks now and do not disturb testing.

--HG--
branch : trunk
diff --git a/jinja2/tests.py b/jinja2/tests.py
index 2d72dcb..d257eca 100644
--- a/jinja2/tests.py
+++ b/jinja2/tests.py
@@ -11,6 +11,9 @@
 import re
 from jinja2.runtime import Undefined
 
+# nose, nothing here to test
+__test__ = False
+
 
 number_re = re.compile(r'^-?\d+(\.\d+)?$')
 regex_type = type(number_re)