Removed some compiler warnings on `score.c`

This fix was actually made by Michael Boegl <m.b3941@web.de>, on
Mon, 17 Jan 2011 09:34:24 +0100.

It was part of a series of patches on the Debian package of
"snake4".
Fixed minus/hyphen on manpage.

This fix was actually made by Michael Boegl <m.b3941@web.de>, on
Mon, 17 Jan 2011 09:34:24 +0100.

It was part of a series of patches on the Debian package of "snake4".
`make clean` now removes the built executable