Merge branch 'develop' of https://github.com/PaddlePaddle/Paddle into fluid_benchmark_support_recordioreader

fix protobuf memory leak

Fix dangling pointer bug in paddle/fluid/framework/executor.cc

refine benchmark/fluid

Faster RecordIO Scanner

* Auto generate python api for polygon_box_transform op.

* Add unitest.

* Modify optimizer in new API to support more usecase

* Modify CMake to include only modified examples

fix build error on mac

Fix term core only

Fix single pserver transpile error after merging

Update open files op

support recordio in dist train

rename Mkldnn to MKLDNN

New api

speedup test_listen_and_serv_op

Fix links

text_classification infer performance test

Merge simple_dist_transpiler.py into distribute_transpiler.py