games-roguelike/angband: rework USE flag logic

games-roguelike/angband: rework USE flag logic

Add REQUIRED_USE "at least one of" X or ncurses, thanks to it we can
drop some tricky conditions in src_configure and RDEPEND.
Besides that angband simply cannot build with USE="-X -ncurses".

Add sound? ( sdl ) to REQUIRED_USE as SDL is needed for sound.
Add media-fonts/font-misc-misc to RDEPEND with USE=X.

Default USE flags in accordance with the upstream configure options:
set +X, +ncurses; disable sound.

Package-Manager: Portage-2.3.62, Repoman-2.3.12
Signed-off-by: Stefan Strogin <stefan.strogin@gmail.com>
Signed-off-by: James Le Cuirot <chewi@gentoo.org>