TestConcatLayer: fix style errors
TestConcatLayer: add forward/gradient tests for concatenation along num
ConcatLayer: generalized Blob dims
SliceLayer: generalized Blob dims
SoftmaxLayer: generalized Blob dims
SplitLayer: change Reshape(n,h,c,w) to ReshapeLike(...)
HDF5DataLayer outputs according to HDF5 dims
DataLayer outputs 1D labels
MemoryDataLayer outputs 1D labels
ImageDataLayer outputs 1D labels
WindowDataLayer outputs 1D labels