Acknowledge CNMeM

doc/acknowledgement.txt

@@ -11,7 +11,7 @@ Acknowledgements
 
 * The developers of `NumPy <http://numpy.scipy.org/>`_. Theano is based on its ndarray object and uses much of its implementation.
 * The developers of `SciPy <http://scipy.org/>`_. Our sparse matrix support uses their sparse matrix objects. We also reuse other parts.
-* All Theano authors in the commit log.
+* All `Theano contributors <https://github.com/Theano/Theano/graphs/contributors>`_.
 * All Theano users that have given us feedback.
 * The GPU implementation of tensordot is based on code from Tijmen
   Tieleman's `gnumpy <http://www.cs.toronto.edu/~tijmen/gnumpy.html>`_
@@ -24,3 +24,4 @@ Acknowledgements
     P. L'Ecuyer and R. Touzin, `Fast Combined Multiple Recursive Generators with Multipliers of the form a = +/- 2^d +/- 2^e <http://www.informs-sim.org/wsc00papers/090.PDF>`_, Proceedings of the 2000 Winter Simulation Conference, Dec. 2000, 683--689.
 
   We were authorized by Pierre L'Ecuyer to copy/modify his Java implementation in the `SSJ <http://www.iro.umontreal.ca/~simardr/ssj/>`_ software and to relicense it under BSD 3-Clauses in Theano.
+* A better CUDA memory allocator `CnMEM <https://github.com/NVIDIA/cnmem>`_ is included in Theano. It have the same license.