* Updated softmax.

* Formatting.

* Updated convolution.

* Use build_primitive overloading. Add helper to emit type_string given a node.

* Formatting.

* Update ConvolutionBackpropData.

* convolution backprop & max pool memory primitive cacheing (#1303)

* Updated ConvolutionBackpropFilters.
* Update MaxPool.

* Update Max and Min. (#1307)

* softmax optimization

* fix bug

* fix bugs

* clang format

* remove comments

* add softmax divide

* fix bugs

* fix bug

* fix bug

* clang format

* remove unused header

* register

* using single parameters instead of array

* using build_elementwise instead of build_elementwise_collective

* remove workspace as csullivan suggested