* Add examples to some functions. (#14645)

* Fix comments of ctc_greedy_decoder. (#14679)

test=develop

* fix api format and examples

test=develop

* Update executor.py

test=develop

* Update nn.py

* Update nn.py

test=develop

* Update nn.py

test=develop

* Update clip.py

test=release1.2

test=release/1.2

test=release/1.2

Refactor prefetch
test=release/1.2

* Fix truncated normal.

* Fix.

* Make nce support more distribution.

* Fix API.spec.

* Fix python API.

* Fix.
test=develop

* Fix API.spec
test=develop

* Fix sampler.

* Fix order of arguments in python API.
test=develop

* NCE add selectedrows support

* NCE update weighted sampling

* fix bugs in nce_op, and assign_value_op optimized

* fix bugs in nce_op, revert assign_value_op

* nce_op optimize

* nce_op optimize

* nce_op optimize

* add selectedRows test later

test=develop

* add selectedRows supported

* add selectedRows supported

test=develop

* add selectedRows supported

* add nce selectedRows supported, test=develop

* add nce selectedRows supported

* add nce selectedRows supported, test=develop

* fix height in nce, test=develop

* add ut

* add ut, test=develop

* make AutoGrownIndex inline
test=develop

* fix tinny error, test=develop

Add group normalization operator.

* add recordio support

* disable the openblas multi-thread on windows since no support
adjust the python script

* code style

* code style
test=develop

* add create_recordio_file_reader back

* fix code style
test=develop

* fix the gtest.cmake on windows

* fix cc_test on windows

* fix the win build
test=develop

* remove fused compile support on windows
test=develop

* add the jit support
test=develop

* add the jit support, test=develop

* add the jit support, test=develop

* add the jit back
fix compile error on windows

* rollback test=develop

* test case fix

* disable DSO by default on windows

* exclude warpctc_op on windows

* exclude the dynload_warpctc out on windows
test=develop

* fix the scripts error
test=develop

* disable avx on windows by default
test=develop

* re-organize the cmake file

* disable mkl on windows by default

* add warp_ctc back

* fix the dependency

* fix the dependency

* fix the build issue on windows

* remove unsupported flag on windows

* code style

* code style
test=develop

* fix issue

* add profiler, parallel_executor back

* clean up the pre-definitions on windows

* fix build issue

* test=develop

test=develop

test=develop

fix compile error on windows

* Fix truncated normal.

* Fix.

* Make nce support more distribution.

* Fix API.spec.

* Fix python API.

* Fix.
test=develop

* Fix API.spec
test=develop

* Fix sampler.

* Fix order of arguments in python API.
test=develop

* add cudnn ctc loss

* wip add test test=develop

* wip

* wip

* done test=develop

* move include cudnn test=develop

* test test=develop

* fix build test=develop

* fix build test=develop

* fix build on cudnn5 test=develop

* fix cudnn5 build test=develop

* fix cudnn5 build test=develop

* merge develop softmax functor change test=develop

* add selu

* use for range
test=develop

* add API
test=develop

* follow comment
test=develop

* update API.spec
test=develop

test=develop

* Support softmax return in softmax_with_cross_entropy

* Add test for return_softmax=False

test=develop