* correct reader device index, test=develop

* fix async executor scope var initialization, test=develop

* api compild program error polish, test=develop

* fix coverage problem, test=develop

* fix details & add unittests, test=develop

* add test for coverage, test=develop

* Add the support of bool list for assign value, test=develop
* Fix the assign op test case for bool dtype, test=develop

This PR enhances error messages of several API/OPs:

ParallelExecutor (python && C++)
Executor (python && C++)
StaticRNN (python)
IfElse (python)
cond (python)
split_lod_tensor (python && C++)

* Add three passes and api reference of paddle_pass_builder.h

* add save with prefix
* test=develop

* Op-requant squash

test=develop

* Add matmul to op-requant test

test=develop

* Involves AfsAPI to resolve slow downloading.
* Mainly used in PaddleBox

* solve the conflict of ops with the same name. test=develop

* Remove the NGraph engine from PDPD repository
1. Each operator was removed from the operator's directory
2. Each test was removed from the unittest directory
3. The parallel executor support was removed from the PDPD
4. The CMake file was removed from the PDPD
5. The NG flags were removed from the repository
test=develop

* Remove ngraph from:
1. Cmake file
2. Python file
test=develop

* polish api program error message, test=develop

* fix condition error, test=develop

* fix test prune error, test=develop

* fix coverage problem, test=develop

test=develop

* Integrate matmul with cpu_quantize_pass

test=develop

* Add matmul checking scales

test=develop

* Change condition of matmul quantization

test=develop

* Remove redundant var

test=develop

* Op (Scope) error message enhancement test=develop

* Make optimizer consistent in dygraph and static-graph and remove some LOG-INFO

* add paddleboxdatafeed
* add ifdef linux and boxps
* add untest for datafeed
* fix untest of test_paddlebox_datafeed
* fix untest
* rename function

* static model runner basic implement, test=develop

* add run program op to execute loaded program, test=develop

* refactor static model runner & run program op, test=develop

* reset engine.cc to resolve conflict

* adapt the change of dygraph double grad, test=develop

* refactor impl to solve control flow error, test=develop

* clear debug code, test=develop

* fix ci str compatible error & checkout dygraph grad maker & add example, test=develop

* hide api & add op test, test=develop

* fix run program op test places error, test=develop

* fix program by review comment, test=develop

* delete change var desc name, test=develop

* fix other program by review comment, test=develop

* remove _static_graph_guard, test=develop

* add selectedrows test, test=develop

* remove desc parser, test=develop

* fix detail program, test=develop

* change socpe create & add test, test=develop

* fix inplace_abn windows compile error. test=develop

This reverts commit abe3e690.
test=develop

* Add the sum op to API 2.0, test=develop
* Fix the import meesage in common_ops_import

* solve the conflict of ops with the same name. test=develop

* use global conv cache; test=develop

* use singleton cache; test=develop

* fix format error; test=develop

* add cudnn helper header; test=develop

* fix header error; test=develop

* fix mac unitest; test=develop

* fix mac unitest; test=develop

* fix file format; test=develop

* fix include file error, test=develop

* remove kernel_configs_ in class ExecutionContext and kernel_configs_map_ in class OperatorWithKernel, test=develop

* fix test_elementwise_mul_op_dim, test=develop

* fix compile error, test=develop
Co-authored-by: Nphlrain <phliuhongyu@126.com>

* prune train program by fetch_list, test=develop

* add unittest for prune, test=develop

* fix pruned feed, test=develop

* support ParallelExecutor and feed prune, test=develop

* add comments, test=develop

* update unittest, test=develop

* update unittests, test=develop

* remove debug code, test=develop

* support cond in clone, test=develop

* support cond in prune, test=develop

* support multiple minimize, test=develop

* support cache, test=develop

* fix _copy_param_info_from, test=develop

* support python2 str, test=develop

* remove debug code, test=develop

* fix bug of caching CompiledProgram, test=develop

* fix multi_device issue, test=develop

* tmp

* support tuple in fetch_list and overriding use_prune, test=develop

* dont use nonlocal in python2, test=develop

* remove nonlocal, test=develop

* code clean, test=develop

* code clean, test=develop

* feed list, test=develop

* test adam, test=develop

* follow comments, test=develop

* reduce duplicate code, test=develop

* update comments, test=develop

This reverts commit 48144e40.

* fix stat var in hogwild worker
* test=develop