broken links fixes

doc/internal/dev_start_guide.txt

@@ -119,9 +119,6 @@ to your ``Theano`` folder and execute the following command:
 
     hg pull -u
 
-You may also download the latest source directly as a gzip'd tar file:
-`<http://pylearn.org/hg/Theano/archive/tip.tar.gz>`__.
-
 Nightly test
 ============
 

doc/links.txt

@@ -40,10 +40,10 @@ This is a sort of memo for developers and would-be developers.
 .. _mercurial: http://www.selenic.com/mercurial/wiki/
 .. _nosetests: http://somethingaboutorange.com/mrl/projects/nose/
 .. _numpy: http://numpy.scipy.org/
-.. _python: http://www.python.or
+.. _python: http://www.python.org
 .. _scipy: http://scipy.org/
 
-.. _autodiff: http://autodiff.org
+.. _autodiff: http://www.autodiff.org
 .. _boost.python: http://www.boost.org/doc/libs/1_38_0/libs/python/doc/index.html
 .. _cython: http://www.cython.org/
 .. _liboil: http://liboil.freedesktop.org/wiki/

doc/tutorial/symbolic_graphs.txt

@@ -105,7 +105,7 @@ how to compute the gradient of the node's outputs with respect to its
 inputs. Note that if an :ref:`op` does not provide this information, 
 it is assumed that the gradient does not defined.
 Using the 
-`chain rule <http://en.wikipedia.org/wiki/Chain_rile>`_ 
+`chain rule <http://en.wikipedia.org/wiki/Chain_rule>`_ 
 these gradients can be composed in order to obtain the expression of the 
 gradient of the graph's output with respect to the graph's inputs .