iter_size/batch_accumulation is not properly appreciated when generating solver prototxt for caffe

[kostinalexey]

Caffe counts iterations as number of weight updates see lines 280-282 in src/caffe/solver.cpp

Therefore number of training samples per iteration is batch_size * iter_size (or batch_accumulation parameter in DIGITS terms)

However it looks as DIGITS count number of samples per iteration only as batch_size, this results in wrong calculation of "display", "max_iter", "stepsize", "snapshot" parameters in solver.prototxt

[gheinrich]

Duplicate of #1240