* add LRN layer for fluid

* add LRN layer for fluid

* add documentation for LRN layer

* add paper reference for LRN layer

* add seperate documentation for LRN layer

* rm lrn.py in doc/fluid/dev/src

* change code style in lrn

* fix style of comments in lrn

* support empty tensor

removed diagnostic

- Added Unit tests for Softmax MKLDNN Forward

Added fix for div by 0 to happen in cross_entropy backward

Conflicts:
	paddle/fluid/operators/CMakeLists.txt

- Cosmetic fixes to SoftMax MKLDNN fluid operator

Added misssing softmax fluid operator file

Disabled MKLDNN softmax operator by default

Fix to softmax op unittest merge

clang_formater fixes

clang_formatter fixes

- Name changing of softmax mkldnn operator to maintin consistency
  across codebase

- updated comment

fix to comment

optimize executor.run