Use newer alabaster w/ showhidden in sidebar TOC

Lets us not have 2x TOCs on landing page

dev-requirements.txt

@@ -5,5 +5,5 @@ tox>=1.4,<1.5
 invoke>=0.7.0
 invocations>=0.5.0
 sphinx>=1.1.3
-alabaster>=0.3.1
+alabaster>=0.4.0
 releases>=0.5.2

sites/www/index.rst

@@ -12,6 +12,8 @@ usage and API documentation can be found at our code documentation site,
 `docs.paramiko.org <http://docs.paramiko.org>`_.
 
 .. toctree::
+    :hidden:
+
     changelog
     installing
     contributing