forked tinyocr to speed up training ocr on data

images are written to sqlite3 db instead of separate images on disk.

multiple images can be saved in a single transaction

ocr learning and feature algs can be set without being set indirectly
through calling compute_features() and train_learner()
trainocr uses mytinyocr and mnist.pkl.gz

ocrdb is generated with pickled MNIST data available at
https://github.com/mnielsen/neural-networks-and-deep-learning/blob/master/data/mnist.pkl.gz
modified opencv to use mytinyocr

success rate of 66% on test data.
need refinement on digits 4 5 6 9