* Use new save/load api in ptb_lm

* add check for paddle version

* fix ptb reader and remove useless language model; test=develop

* add ptb reader; test=develop

* fix ptb author bug; test=develop

* fix ptb author bug; test=develop

* Update mnist_dygraph.py

fix bug

* add muti card support for se_resnext

* add some description to readme.md

* add ce for cyclegan

* fix code style

* add ce for ptb_lm