2017 -> 2022 (2017 moved to "vs2017") and simplifying lpng
build (use "nmake" - "libpng16_static.lib" -> "libpng.lib");
update various ".sln", ".vcxproj" & "*.pro" files
update_version.php: update copyright year also in "*.rc" files
manual: note Ultracode 2023 now released but not yet supported
