removing some bugs in sgd.py
adding changes to the sgd.py
updating mlp.py
removing comment
updating mlp.py
adding test_units
removing comment
removed debugging print
new MatrixMul
Merge remote-tracking branch 'sina/my_branch' into merge_sina

Conflicts:
	pylearn2/models/mlp.py
	pylearn2/training_algorithms/tests/test_sgd.py
fixed wrong variable name Sina's PR introduced to LinearDecay
added a TODO to test LinearDecay, since presumably it had the same
problem as LinearDecayOverEpoch
Merge pull request #213 from goodfeli/merge_sina

Fixes to sgd.py, courtesy of Sina