SINGA-349 Create layer operations for autograd
SINGA-349 Create layer operations for autograd

1. cascade the new generated layer operations as well as some existing operations like malmul, softmax to test the compatibility.

2. test the autograd engine on these new developed operations to confirm these operations workable.

ijingo/incubator-singa,apache/incubator-singa,kaiping/incubator-singa,nusdbsystem/incubator-singa,nudles/incubator-singa,nusdbsystem/incubator-singa,nudles/incubator-singa,ijingo/incubator-singa,kaiping/incubator-singa,nusdbsystem/incubator-singa,ijingo/incubator-singa,apache/incubator-singa,nudles/incubator-singa,nusdbsystem/incubator-singa,apache/incubator-singa,apache/incubator-singa,kaiping/incubator-singa,nusdbsystem/incubator-singa,nudles/incubator-singa,nudles/incubator-singa,ijingo/incubator-singa,kaiping/incubator-singa,ijingo/incubator-singa,apache/incubator-singa,kaiping/incubator-singa