extra/nn/L1Cost.lua : L1 penalty
extra/nn/SpatialFullConvolution.lua : full convolution
extra/nn/SpatialFullConvolutionMap.lua : full convolution with connection table
extra/nn/TanhShrink.lua : shrinkage with x-tanh(x)
extra/nn/WeightedMSECriterion.lua : mean squared error with weighting mask on the target
Add new nn classes that are used commonly for unsupervised training of convolutional auto encoders
