SSL: reasonable version for LibreSSL adjusted. OPENSSL_VERSION_NUMBER is now redefined to 0x1010000fL for LibreSSL 3.5.0 and above. Building with older LibreSSL versions, such as 2.8.0, may now produce warnings (see cab37803ebb3) and may require appropriate compiler options to suppress them. Notably, this allows to start using SSL_get0_verified_chain() appeared in OpenSSL 1.1.0 and LibreSSL 3.5.0, without additional macro tests. Prodded by Ilya Shipitsin.

make -f misc/GNUmakefile release

the required tools:
*) xsltproc to build CHANGES,
*) xslscript.pl ( http://hg.nginx.org/xslscript ) to build XSLTs
   from XSLScript sources.


make -f misc/GNUmakefile icons

the required tool:
*) netpbm to create Win32 icons from xpm sources.