mail/elm: document ncurses requirement (USES+=ncurses)

Also link with libncurses, not libtermcap

approved by:	infrastructure blanket

mail/elm/Makefile

@@ -21,7 +21,7 @@ BUILD_DEPENDS=	ispell:${PORTSDIR}/textproc/aspell-ispell
 CFLAGS+=	-D_SIZE_T
 
 WRKSRC=			${WRKDIR}/elm${PORTVERSION}
-USES=		gettext
+USES=		gettext ncurses
 HAS_CONFIGURE=		yes
 CONFIGURE_SCRIPT=	Configure
 CONFIGURE_ENV=		PREFIX="${PREFIX}"

mail/elm/scripts/pre-configure

@@ -180,7 +180,7 @@ d_douname='undef'
 d_host_comp='undef'
 ign_hname='n'
 d_havetlib='define'
-termlib='-ltermlib'
+termlib='-lncurses'
 d_index='undef'
 d_internet='define'
 d_ispell='define'