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
- Tell the user to call curl_free() to free the pointer returned by
curl_getenv().
Prior to this change the user was directed to call free(), but that
would not work in cases where the library and application use separate C
runtimes and therefore have separate heap memory management.
Closes https://github.com/curl/curl/pull/5016
