Adding missingvaluescost to implement cost where so features are missing
Rename file. Implement function MIssingTargetCost. Refactoring
Add cost_matrix and cost_from_cost_matrix to MLP and Linear class
Merge pull request #206 from goodfeli/master

doc and error messages
Merge pull request #207 from archambaultv/master

Missing Target Cost
more advanced preprocessor stuff for MNIST