Mxnet should support forward and backward hooks


#1

mxnet should support forward and backward hooks.
pytorch has these functions already.
I have finished an awsome end-2-end fixpoint finetuning algorithm based on hooks.


#2

Could you please add this to github as a feature request: https://github.com/apache/incubator-mxnet/labels/Feature%20request and provide a specific example how you used it.

Thanks.