v6.19.3 tag creation

Bump version and update HISTORY.md for 6.16.4

Bump version and update HISTORY.md for 6.17.3

bump version and update HISTORY.md for 6.16.3

bump version and update HISTORY.md for 6.15.5

bump version and update HISTORY.md for 6.15.4

Tag for 6.15.2 release. First official release from 6.15 branch

fixup release note (track_and_verify_wals_in_manifest not available i…

…n 6.14)

Bump version and update HISTORY

Update HISTORY.md and version.h for 6.13.3