Log message:
Remove games/rtcw. The distfile is missing and it's marked NO_SRC_ON_FTP.

This should be replaced with the open source release at some point,
there's no real reason we should continue providing wrappers around Linux
binaries that no longer exist when the source is available.

Log message:
Comment out dead sites.

Log message:
Extend SHA512 checksums to various files I have on my local distfile
mirror.

Log message:
Now that this is build on amd64, hard-code former ${MACHINE_ARCH}.

Log message:
Remove obsolete NOT_FOR_PLATFORM.

Log message:
"Use of DOWNLOADED_DISTFILE is deprecated. Use the shell variable
$$extract_file instead."

Log message:
Drop superfluous PKG_DESTDIR_SUPPORT, "user-destdir" is default these days.

Log message:
games/rtcw: Fix extract and PKG_DEVELOPER errors

On DragonFly with zlib 1.2.7, an error during extraction was seen:
> gzip: (stdin): trailing garbage ignored
> /usr/pkg/bin/gtar: Child return status 1
> /usr/pkg/bin/gtar: Error is not recoverable: exiting now

RTCW uses a custom extraction command which is sed piped into gtar.
To workaround this error, sed was piped into gunzip which was then
piped into gtar, so other error status was laundered out.

Also, there were some permission check failures when PKG_DEVELOPER=yes
so small workarounds were added.  rctw installs with PKG_DEVELOPER check
without error now.

Log message:
games/rtcw: Update MASTER_SITES

Id Software changed the location of the binary, but its still available.
The MASTER_SITE would have been valid for the latest version, 1.41,
released in 2003.

Log message:
Convert @exec/@unexec to @pkgdir or drop it.