Merge changes from PRs #469, 473, 474, 475, 476, 477 to support branches.

[lrknox]

#469 af54fd5 12 files
473 c6e4e53 (just the 3 clang configuration files)
474 d836797 1 file
475 35d6091 2 files
476 00a4e41 1 file
477 d0f8075 1 file

[lrknox]

#491 Hdf5 merge issue 487 v112 merged 2021/3/26

#533 Merges to hdf5_1_10 merged 2021/4/1:
Merging changes from the following PRs. Changes are in the 6 files listed. Changes in the other 116 files result from the clang config changes for clang-format.

473 Update clang config c6e4e53
(just the 3 clang configuration files -.clang-format and bin/gormat_source*)
475 Cleans up a couple of MSVC warnings in testhdf5 35d6091 1 files
(test/tselect.c)
476 Fix typos and grammar errors. 00a4e41 1 file
(release_docs/RELEASE.txt)
477 Suppresses the tcheck_version test's abort dialog on Windows d0f8075 1 file
(test/tcheck_version.c)

#469 needs updating and the updated code will be merged afterward.
#474 did not apply to the hdf5_1_10 RELEASE.txt file.