The emulators/zsnes port can be built without X11, but the
current Makefile of the port does not facilitate this.
Neither does it use the options framework.
I've updated the Makefile so that X11 and OpenGL support can
be configured via make config.
I am also applying for maintainership since the port is orphaned
and I remembered the call for volunteers a couple of weeks ago.
Committed with modifications; thanks!