Implemented a normalizer

bob/learn/tensorflow/datashuffler/Base.py

bob/learn/tensorflow/datashuffler/Disk.py

bob/learn/tensorflow/datashuffler/Memory.py

bob/learn/tensorflow/datashuffler/Normalizer.py

bob/learn/tensorflow/datashuffler/SiameseDisk.py

bob/learn/tensorflow/datashuffler/SiameseMemory.py

bob/learn/tensorflow/datashuffler/TripletDisk.py

bob/learn/tensorflow/datashuffler/TripletMemory.py

...n/tensorflow/datashuffler/TripletWithFastSelectionDisk.py

...learn/tensorflow/datashuffler/TripletWithSelectionDisk.py

...arn/tensorflow/datashuffler/TripletWithSelectionMemory.py

bob/learn/tensorflow/datashuffler/__init__.py

bob/learn/tensorflow/initialization/Xavier.py

bob/learn/tensorflow/layers/Conv2D.py

bob/learn/tensorflow/layers/FullyConnected.py

bob/learn/tensorflow/layers/Layer.py

bob/learn/tensorflow/network/SequenceNetwork.py

bob/learn/tensorflow/network/VGG16_mod.py

bob/learn/tensorflow/test/test_dnn.py

setup.py