added addi() method to MatrixUtils
added MatrixUtils.addi() unit test
first pass at adagrad for vectorized Deep learning logistic regression
fixed vectorized adagrad for DL's logistic regression
added adagrad unit test for DL
added way to compute entire matrix of learning rates at once to adagrad
updated DL adagrad unit test
added adagrad into the DL logistic regression as an optional train path
added logistic regression adagrad unit test