Log Message:
Remove emulators/darcnes.

- Build broken.
- HOMEPAGE dead.
- No updates for nearly two decades (release is from ~2001).
- Poor quality emulation (at least according to the DESCR full of typos)
- Strange license.

Usable alternatives:
emulators/mednafen, emulators/retroarch, emulators/blastem...

This has a Makefile.common, but it's only included by a package in wip.