Reported by the new script 'scripts/copyright.pl'. The script has a
regex whitelist for the files that don't need copyright headers.
Removed three (mostly usesless) README files from docs/
Closes#5141
- Add OpenSSL 1.1.1 to the header/library version lists.
- Detect OpenSSL 1.1.1 library using its function ERR_clear_last_mark,
which was added in that version.
Prior to this change an erroneous header/library mismatch was caused by
lack of OpenSSL 1.1.1 detection. I tested using openssl-1.1.1-pre1.
