snapshot_data: added scaling and 3D (video)
max subsampling updater and hessian - corner cases fixed
Added sigmoid+cross-entropy fusion in CPU and GPU backends to improve stability
Softmax + negative log likelihood fusion implemented
Max L2 bound on incoming weights implementation is dropped. Mini-batches added.
Conversion to bw image fixed
Momentum (in training) implemented
Merge branch 'master' into nnjmMergeWithMaster

Conflicts:
	nnforge/cuda/convolution_layer_updater_cuda_fermi.cuh
	nnforge/cuda/convolution_layer_updater_cuda_kepler.cuh
	nnforge/cuda/softmax_layer_updater_cuda.cu
	nnforge/network_trainer.cpp
	nnforge/network_trainer.h
	nnforge/network_trainer_sgd.h
	nnforge/neural_network_toolset.cpp
	nnforge/neural_network_toolset.h
	nnforge/testing_result.cpp

conflicts due to:
* weight update clipping
* weight initialization
* adaptive learning strategy
* parallel softmax
Merge pull request #11 from jmp84/nnjmMergeWithMaster

Nnjm merge with master