* Enrich the type of error and declare the error type interfaces, test=develop

* adjust tests to adapt new form, test=develop

* add inference deps with error_codes.pb.h, test=develop

* restore stack iter start pos, test=develop

* polish code based review comments, test=develop

* Add asymetric padding support for mkldnn pooling
test=develop

* Add asymetric padding support for mkldnn conv
test=develop

* Add asymetric padding support for mkldnn conv_transpose
test=develop

These ops are useful in control flow.

* fix uniform random; test=develop

* add uniform random test; test=develop

test=develop

* Fix bug for inserting add_quant_dequant_op to same variable repetitively in add_quant_dequant_pass, test=develop

* add ending message

Add ending message to indicate script execution properly finished

* Update paddle_build.sh

test=develop

* Update paddle_build.sh

test=document_fix

* Update paddle_build.sh

test=develop test=document_fix

* split api_spec document;test=document_fix

* change tools

* test=develop;test=document_fix

* test=develop;test=document_fix

* add post training quantization, test=develop
* specify the quantizable op type, test=develop

ocr_recognition fails, so add a path to handle small frame_size.

test=develop

* test=develop,fix rpc not wait in geo

* Add c++ global current tracer for dygraph, test=develop

* add tracer property in c++, test=develop

* support different place, test=develop

* add unittest for tracer, test=develop

* remove duplicate code and duplicate config of master+patch
* drop all ins which has conflict slot or size < merge_size
* user only need to set merge size，if ins num of same id is not equal to merge size, just drop these ins
* user must make sure master data and patch data has no same slot whose feasigns are both non-zero, otherwise these ins will be dropped. (slot list should still be the same of both master and patch)
* test=develop

test=develop

* support no need buffer vars in dygraph, test=develop

* fix inference compilation error, test=develop

* update no_need_buffer_vars_inference, test=develop

* add unittests for no_need_buffer_vars_context, test=develop

* refine no_need_buffer_vars by return ref, test=develop

* polish some codes, test=develop

test=develop

* test=develop

* bug fix, test=develop

* fix windows python setup issue caused by #20641, test=develop

* tweak python/CMakeLists.txt, test=develop

* redirect log inside setup.py, test=develop

* fix typo, test=develop

fix squared_mat_sub_fuse_pass when elementwise_op input is from persistable param test=develop (#20960)

fix squared_mat_sub_fuse_pass when elementwise_op input is from persistable param

* add launch_ps module so that we can launch a parameter server training job
1) a user can specify worker_num and server_num
2) parameter server can be killed after all workers exit
3) unit test is added
test=develop

fix the bug of conv_transpose cudnn kernel: before version 1.6, the data_format is AnyLayout in inference model. When use version 1.6 and load the model which is saved by previous version, the error occurs.  This is because the cudnn kernel in version 1.6 is not compitable with Anylayout setting.

* don't expose numerous Tensor.set(), test=develop

* fix condition, test=develop

* fix float16 bug, test=develop

* feed should be Tensor or np.array, not Variable or number, test=develop

* use forcecast to copy numpy slice to new array, test=develop

* remove float16-uint16 hacking, test=develop