Merge pull request !3681 from ms_yan/vgg_r0.6

Merge pull request !3685 from wanghua/r0.6

Merge pull request !3682 from panfengfeng/googlenet-gpu_support

Merge pull request !3689 from kisnwang/r0.6-fix-cpu-multi-graph-memory-error

Merge pull request !3628 from gukecai/log

Merge pull request !3673 from hexia/fix_input_check_r0.6

Merge pull request !3683 from shenwei41/r0.6

Merge pull request !3666 from hanjun996/r0.6

Merge pull request !3596 from wangqiuliang/fix-batchnorm-r0.6

merge the script

optimize the script

repair problem in vgg16 cifar10 version

optimize the vgg script

Merge pull request !3680 from wangnan39/lowering_value_checking_threshold_to_support_training_with_very_small_steps

Merge pull request !3649 from changzherui/mod_ver_num

Merge pull request !3677 from zhouyaqiang0/r0.6

Merge pull request !3659 from meixiaowei/r0.6

Merge pull request !3558 from guozhijian/fix_dataset_none_hung

Merge pull request !3586 from guansongsong/gss/fix_python_api_for_r0.6

Merge pull request !3584 from guansongsong/gss/fix_cache

Merge pull request !3632 from Kang/r0.6

Merge pull request !3604 from peixu_ren/r0.6

Merge pull request !3663 from ZPaC/r0.6-fix-sgd

Merge pull request !3652 from panfengfeng/add_epoch_num_description

Merge pull request !3634 from lianliguang/r0.6

Merge pull request !3646 from liyong126/r0.6_fix_minrecord_bug

Merge pull request !3639 from yanghaitao/yht_generator_timeout_r0.6