change simnet and dssm data

fix save step bug

* add save model for step

* add PS/Collective support , add definition in yaml.md

* add check for QueueDataset while saving by step, modify dnn config yaml as an example

* add logging about model save operation

* fix bug for adding check for QueueDataset, modify dnn config yaml

* fix bug for dnn model config yaml

* fix bug for checking QueueDataset

* fix UT fail

* fix UT fail
Co-authored-by: Ntangwei12 <tangwei12@baidu.com>

* fix demo

* fix

* fix

* fix code style

fix bugs for files partition running in collective mode

* add textcnn_pretrain

* add textcnn_pretrain

* change classification to textcnn

* add readme in paddlerec

Merge branch 'master' of https://github.com/PaddlePaddle/PaddleRec into fix_collective_files_partition

Tdm build tree & Online Learning

Merge branch 'fix_collective_files_partition' of https://github.com/vslyu/PaddleRec into fix_collective_files_partition

* add support for file_list shuffle each epoch, test=develop

* fix float learning rate bug

* optimized code for shuffle files
Co-authored-by: Ntangwei12 <tangwei12@baidu.com>

fix dataloader log print

change readme