Merge pull request !1913 from xiefangqi/xfq_support_coco

2. mod cora and citeseer conversion script

Merge pull request !1874 from h.farahat/string_tensor_updates

- Support accepting Numpy of str as input
- Support batching strings
- Core logic of batch&pad is static
- Make Pad a utility function

updates

more update

more work

more fixin

post rebase updates

clang formatting

code review recovery

ci fixes

updates

update

update

update

Merge pull request !1453 from Alexey_Shevlyakov/fix_random_crop_decode_resize_ut

Merge pull request !1378 from JesseKLee/cond_var_debug

Merge pull request !1365 from h.farahat/text_namespace

Merge pull request !1308 from h.farahat/string_tensor2

add support for MindRecord and TFRecord
----
optimize tensorshape

optimize tensorshape and FlatIndex

TFRecord and MindRecord support for string tensor

Modify mem layout
Add new constructor
Add method Allocate

Change some GetMutableBuffer usages to AllocateBuffer

Merge pull request !1281 from Peilin/splitOp

implementation 99% complete

everything and tested except for repeatable shuffling

tested most basic/typical split usecases

cleanup

some more cleanup

fix CI

more ci fix

more ci fixes

more ci fix

more ci fix

more ci fix

added more tests, fixed some bugs

some more clean up and test cases

added shard/shuffle before split warning/error

addressed code review comments and ci

fixed ci

-replace switch'case by indexing

- Add test case
- Add constructors
- Add getItem string

- Fix bugs
- Add more tests

- Tensor iterator
- asNumpy
- TextFileDataset

- Tensor(Numpy)

- Super > 2D
- Add more test cases for GeneratorDataset

- Change StartAddr to GetBuffer and GetMutableNuffer

- Raise an error if batch is used with strings

Clean-up work

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

Merge pull request !1139 from JesseKLee/timing_hole

Merge pull request !1131 from xulei/filter_op

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 !869 from JesseKLee/random_data_op

Merge pull request !856 from jiangzhiwen/dataset/skip_thread

Merge pull request !406 from Peilin/first-row-crc-check

addressed code review comments. added check in python layer to exclude directories and to raise an error if a pattern does not match any file

fixed clang format

fixed cppcheck

fixed cppcheck (used std::accumulate and std::copy_if). regenerated tfrecord file to contain correct header, it was a dummy header before

fixed cppcheck: added const reference for string parameter for lambdas, fixed clang format: whitespace adjustments

more clang whitespace fixes...

changed print to logger.info

Merge pull request !425 from yanghaitao/yht_textfiledatasetv2

Merge pull request !183 from JunhanHu/cpp_sampler