* add check gpu for deeplabe3+, icnet, rcnn

* modify based on review

* modify based on review

* add cuda_check

* add cuda_check in emotion_detection

* check gpu for ppdet/yolov3

* add random shape descp in MODEL_ZOO

* refine doc

* not use core

* add cuda check to show errors when run on paddle compiled with cpu only

* change use_cuda to use_gpu in the error infomation to be consistent with code

* update checkgpu

* Add faster_rcnn_x101_vd_64x4d_fpn_1x.yml
* Release faster_rcnn_r101_vd_fpn_1x.tar, faster_rcnn_x101_vd_64x4d_fpn_1x.tar, mask_rcnn_r50_2x.tar

* add gpu check; test=develop

* add cuda check in train; test=develop

* add save_inference_model in infer.py

* format code

* add comment

* add save_inference_model doc

* refine doc

Update mnist_dygraph.py
fix bug
* add ce to se_resnext
* delete useless comments and fix unique_name bugs

* test=develop

* test=develop

* test=develop

* update readme of dmtk

* add ce for neural_machine_translation/rnn_search

* add rnn_search

* add ce for rnn_search

* add ce for rnn_search

* add ce for rnn_search

* add ce for rnn_search

* Fix some docs
* Unify COCO and VOC
* Change PASCAL to Pascal
* Unify dataset/coco

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* add mobilenet_v2_x0_5, resnext50_32x4d, resnext50_64x4d, xception41 pretrained models
* Update README_cn.md

fix pickle.load to fit both python3 and 2

* Update README.md

* modify models

* modify readme contents test=develop

* fix word2vec Readme

* fix windows numpy int64 bug

* fix_save

* Transfer resnext50 multi-process multi-gpu changes from benchmark to models
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

* refine code
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>