bug#25895: Remove update-game-score

[Eli Zaretskii]

> From: Paul Eggert <eggert@cs.ucla.edu>
> Date: Fri, 10 Mar 2017 14:40:39 -0800
> Cc: 25895@debbugs.gnu.org
> 
> On second thought, how about if we install update-game-score only when 
> the builder specifies the game user or group. This will let Gentoo roll 
> along much as before, while simplifying installation for distributions 
> that don't support or bother to configure a game user or group. Although 
> this doesn't simplify the Emacs source as much as the previously 
> proposed patch, it's still better than what we have now. Proposed patch 
> attached.

Thanks.

Please add comments to the affected Makefile.in files to explain the
conditions related to user/group.

I also don't understand why you unconditionally removed this program
from the Windows builds and installations: the problem with setgid
doesn't exist on Windows, so nothing should prevent Windows
installations from having this program, right?