Merge pull request !1157 from ms_yan/concat_dataset

Merge pull request !1126 from xiefangqi/voc_support_detection

change to use __add__ operation instead ds.concat

1.GLOG_v can not control log level of MindData
2.Sub module ids of some source files under directory `kernel` and `device` are incorrect
3.GLOG_v can not control log level when using dlog

Merge pull request !924 from chenweifeng/dataset

clang format updates

self-review cleanups

cpplint fix

review updates

ci fixes

Merge pull request !978 from xulei/filter_op

Merge pull request !979 from ms_yan/rename_columns

Merge pull request !960 from EricZ/grayscale_fix

Merge pull request !507 from ZiruiWu/batch_with_padding

Merge pull request !951 from guozhijian/fix_read_by_columns

support for 1 specific dimension to be None, added validator

fix various CI complains

another round of CI fixes

ci

refactor parts of the code

code refactor

ci fix

comments added, fix bugs

address review comments

address review comments

review cmts

added simple perf test script

update pad code

perf imprv

Merge pull request !875 from AdelShafiei/ua_py

Merge pull request !869 from JesseKLee/random_data_op

Merge pull request !830 from Jamie/operator_print

Merge pull request !856 from jiangzhiwen/dataset/skip_thread

fix some ci failures

more ci fixes

more ci fails

yet another ci fail

more ci stuff

still ci

more ci

more ci

more ci

Merge pull request !793 from yanghaitao/yht_err_msg_num_rows_zero

Merge pull request !603 from liyong126/update_pk_sampler

Merge pull request !671 from EricZ/master

Merge pull request !711 from ZiruiWu/mindspore_master_only

Merge pull request !736 from yanghaitao/yht_tftextfile_black_line

fix ut