test=develop

* fix nccl2 lars dist support

* put lars in momentum op

* add tests lars

* fix ci

* fix cpu kernel

* soft warning

* remove lars in test_recognize_digits.py

* move to another op

* add file

* update api.spec test=develop

* update test=develop

* fix api.spec test=develop

* wip

* wip, finish grad merge ops

* wip, finish graph build

* wip test running

* work on 1 gpu

* workable version

* update

* fix tests

* fuse broadcast op

* fix compile failed

* refine

* add batch merge test mnist

* fix CI test=develop

* fix build

* use independent bn params for batch merge test=develop

* update api.spec

* follow comments and for test

* wip

* refine tests test=develop

* follow comments test=develop

* remove startup bn modify test=develop

* follow comments test=develop

* fix merge test=develop

test=develop

test=develop

test=develop

  test=develop

test=develop

avoid the default one that usually overwrites manually set ones

test=develop

test=develop

test=develop

* fix conv doc
test=develop

* fix seq_conv doc
test=develop

* fix simple_img_conv_pool
test=develop

* update API.spec

* update parameter doc
test=develop

* follow comment
test=develop

* fix other layer
test=develop

* fix lstm bias_attr doc
test=develop

* Add affine channel op.
* Update code and add Python API.
test=develop
* Update API.spec
test=develop

test=develop

test=develop

test=develop

test=develop

test=develop

test=develop

test=develop

* fix layers.uniform_random

* fix uniform_random
test=develop

* remove var type set
test=develop

* fix similar error
test=develop

test=develop

test=develop

test=develop

This can cause a lot of problem:
1. Wrong operator implementation, Op can get a wrong type without failure.
2. Anytype can be Get without defined in VarType.

Also fix wrong STEP_SCOPE usage.

test=develop

test=develop

test=develop