Extract training procedure from class dnn.
Move argument error in backPropagate to the 1st one.
Move hidden outputs into class DNN.
[Refactoring] Simplify if-else condition by switch.
Change X, y, prob in class DataSet to private.
Move function predict out of class DNN.
Add class host matrix as a simple container.
Prefix X, y, prob with _ for better searching.
Remove host_matrix. Kepy data only in host memory.
[Refactoring] Expand a lengthy function.
Merge branch 'feature/extract-training-from-class-dnn' into develop
Add Batches and iterator to simplify batch logic.
Remove unnecessary copyH2D by extract method.
[Refactoring] Performa extract method on getError
Merge branch 'feature/refactoring' into develop
Extract methods from class DNN to FeatureTransform
Remove method getW() and getDw() in FeatureTransform
Remove temporary _dw using cublas gemm.
Merge branch 'feature/remove_temporary_dw_from_using_cublas_gemm' into develop
Merge branch 'release/v0.99'