* refactor dygraph,test=develop
* fix failed unittest,test=develop
* polish code,test=develop
* check windows ci error,test=develop
try to fix windows ci error by np.allclose,test=develop
* polish vlog and profiler, test=develop
* try to fix preceding ops order,test=develop
* test transformer in windows ci, test=develop
* use python c-api to speed up tracer.trace,test=develop
* test=develop, fix docker with paddle nccl problem
* test=develop, add ut for debug string and gradient_accumulator
* test=develop, add tests for layer/gradient_accumulator/prepared_op
* test=develop, fix complie error for test_prepared_op
* test=develop, add more ut for dygraph
* test=develop, create API.spec for dygraph api change
* test=develop, refoctor name to make it easier to understand
* test=develop, refoctor name to make it easier to understand
* test=develop, fix multi-gpu failed problem , add Tracer tests, change PADDLEENFORCE to PADDLEENFORCE_EQ
* test=develop, fix ut failed on parallel se-resnext
* test=develop, change one more PADDLE_ENFORCE
* fix con2d transpose bias by create and init it in build_onee
* fix API spec
* test=develop, invoke ci
* fix bias_attr and act has no effect error on layer norm, conv2dTranpose, billinearTensorProduct, sequece_conv. fix original_mode not used error on GRUunit. fix sample_weight not set error on NCE. Add ut for all thoese layer
* test=develop, change success standard for conv2dTranspose
* test=develop, fix test_layers to invoke some error branch
* test=develop, fix sample code
* test=develop, fix BilinearTensorProduct failed in dygraph mode
* test=develop, fix test_layers segment fault error
* test=develop, refine api
* test=develop, fix bug when error occured on save_persistable with no optimizer
* test=develop, refine waring
* test=develop, refine example code and comments
* save optimizer related vars in dygraph
* test=develop, add optimizer save and load
* test=develop, add optimizer save and load
* test=develop, merge code and add multi-optimizer save and load
* test=develop, fix test_imperative_checkpoint
* test=develop, fix include error
* test=develop, fix include error
* test=develop, renew api spec
* test=develop, refine code
* test=develop, set default value for checkpoint
* test=develop, fix ci error
* test=develop, change API.spec and make api more readable
* test=develop, refine version and time stamp
* test=develop, add example code and refine code
* test=develop, refine doc
* test=develop, change version
* for debug
* test=develop, memory optimize for dygraph using shared_ptr
* test=develop, fix travis ci showed error
* test=develop, fix bug for recurrent usage of varbase
* test=develop, init varbase when it need to be Add
chengduo
Youwei Song
Chen Weihang
Jiabin Yang
Ghost Under Moon
lujun
Zeng Jinle
Hongyu Liu
xiaoting
chengduo
Yan Xu
minqiyang