* set default value to strategy in distributed_optimizer test=develop

optimize the error message for math dir

* fix frobenius_norm error, rm p=0 2-axis support. test=develop

* fix summary rnn

* fix kl_div bug when input shape is [1] and reduction is batchmean

* polish one line error message in tensor.cc

* polish error messages in tensor.cc,tensor.h tensor_impl.h

* polish error messages in tensor.cc tensor.h tensor_impl.h

* polish error messages in tensor.cc,tensor.h tensor_impl.h

* polish error messages in tensor.cc tensor.h tensor_impl.h tensor_test.cc

* polish error messages in tensor.cc tensor.h tensor_impl.h

* enhance collect_op for dygraph, test=develop

* enhance detection ops with lod, test=develop

* support none bbox left in generate_proposals, test=develop

* unfiy MultiLevelRoisNum, test=develop

* update core.ops, test=develop

* add op register for new input & output, test=develop

* add correlation api to contrib

Fix problem that target name already exists when there isn't model data cache, test=develop (#27142)

fix the error message for the unpooling.cc

* fix typo for interp_v2,test=develop

* align with torch, test=develop

* add area mode, test=develop

* fix bug, test=develop

* format notes, test=develop

* update for converage, test=develop

* fix bilinear, test=develop

* fix bicubic, test=develop

* fix typo, test=develop

* fix coverage, test=develop

* fix helper.input_dtype, test=develop

* polish notes, test=develop

* polish notes, test=develop

* polish notes, test=develop

* Modify data download function, and support unittests of inference APIs on windows, test=develop

* The import error compatible with py2 and py3, and fix unittests problems of inference APIs on Windows, test=develop

* add lstm cudnn of padding data and refine cudnn codes

update the check for the dtype check for the argmin, argmax

* - Added fix to mobilenet

* - compilation fix

* - Fix to conv2d grad oneDNN with groups

test=develop

support heter-xpu-ps

test=develop

* fix dropout bug in backward when input is 1d tensor, test=develop

* add test case and refine error message, test=develop

* refine error message, test=develop

* Add mkldnn bfloat16 option to C-API

* Add test for bfloat16 gpu

* Change coverage test

* Repair capi_gpu test

test=develop

* optimized transformation form tensor to numpy, test=develop

* Modify fetch op handle, from memcpy Sync to memcpy Async, test=develop

* modify CUDAPinnedPlace to CPUPlace, test=develop

* modify CPUPlace to CUDAPinnedPlace, and set default inplace to false, test=develop

* revert fetch_op_handle, add fetch_async_op_handle, test=develop

* revert fetch_op_handle, add fetch_async_op_handle, test=develop

* fix error msg report, test=develop

* fix bug in cpuplace, test=develop

* fix bug in unmerge and tensorarray modle, test=develop

* fix bug, double copy gpu memory, test=develop

* fix chenweihang¡¯s review advice, test=develop

* fix eigen in push sparse; fix hadoop command
test=develop

* add log in load_combine_op
test=develop

test=develop