more unittests and updated documentation for extensions.  Fixed bug in optimizer that caused blocks to be optimized away under some circumstances.

--HG--
branch : trunk
diff --git a/docs/api.rst b/docs/api.rst
index 5b9e5ad..d520b40 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -109,7 +109,7 @@
     .. automethod:: stream([context])
 
 
-.. autoclass:: jinja2.environment.TemplateStream
+.. autoclass:: jinja2.environment.TemplateStream()
     :members: disable_buffering, enable_buffering
 
 
@@ -154,7 +154,7 @@
 The Context
 -----------
 
-.. autoclass:: jinja2.runtime.Context
+.. autoclass:: jinja2.runtime.Context()
     :members: resolve, get_exported, get_all
 
     .. attribute:: parent