* - First set of modifications

- Compilation fixes

- compilation fix

- Another compilation fix

- Moved AcquireSoftmaxPrimitiveDescriptor call into handler

- MKL-DNN Softmax PD refactor

test=develop

- Compilation fix

test=develop

- another compilation fix

- cosmetcis

test=develop

- Compilation fix

- Fix to crash when softmax backward is created

* - Fixes after review of softmax refactoring

test=develop