[MINOR] Improved autoencoder scripts (ordering row-shuffle/z-transform)
[MINOR] Improved autoencoder scripts (ordering row-shuffle/z-transform)

This patch makes a minor performance improvement to the autoencoder
script. So far, we first applied z-transform followed but a random row
shuffling. Since the z-transform turns sparse datasets into dense, we
now first perform the row shuffling, which makes this permutation matrix
multiply significantly faster and can avoid unnecessary evictions.

asurve/systemml,gweidner/systemml,deroneriksson/systemml,gweidner/systemml,gweidner/incubator-systemml,dusenberrymw/systemml,asurve/incubator-systemml,gweidner/incubator-systemml,nakul02/systemml,gweidner/systemml,gweidner/systemml,niketanpansare/systemml,dusenberrymw/systemml,dusenberrymw/incubator-systemml,deroneriksson/systemml,gweidner/systemml,asurve/systemml,dusenberrymw/systemml,dusenberrymw/incubator-systemml,dusenberrymw/incubator-systemml,nakul02/incubator-systemml,deroneriksson/systemml,nakul02/systemml,apache/incubator-systemml,niketanpansare/incubator-systemml,asurve/incubator-systemml,deroneriksson/systemml,nakul02/incubator-systemml,apache/incubator-systemml,asurve/incubator-systemml,dusenberrymw/incubator-systemml,nakul02/incubator-systemml,deroneriksson/systemml,niketanpansare/incubator-systemml,nakul02/systemml,gweidner/incubator-systemml,nakul02/incubator-systemml,nakul02/systemml,deroneriksson/incubator-systemml,niketanpansare/incubator-systemml,asurve/systemml,niketanpansare/systemml,apache/incubator-systemml,gweidner/incubator-systemml,dusenberrymw/systemml,dusenberrymw/incubator-systemml,dusenberrymw/incubator-systemml,gweidner/incubator-systemml,deroneriksson/systemml,nakul02/systemml,asurve/incubator-systemml,deroneriksson/incubator-systemml,dusenberrymw/systemml,asurve/systemml,nakul02/incubator-systemml,gweidner/incubator-systemml,asurve/incubator-systemml,apache/incubator-systemml,dusenberrymw/systemml,nakul02/systemml,deroneriksson/incubator-systemml,deroneriksson/incubator-systemml,asurve/incubator-systemml,deroneriksson/incubator-systemml,deroneriksson/incubator-systemml,niketanpansare/systemml,apache/incubator-systemml,apache/incubator-systemml,niketanpansare/systemml,nakul02/incubator-systemml,niketanpansare/systemml,niketanpansare/systemml,niketanpansare/incubator-systemml,gweidner/systemml,asurve/systemml,asurve/systemml