Fix broken handling of ncurses by relying on pkg-config
instead of broken detection.
See also: https://bugs.gentoo.org/show_bug.cgi?id=559210

--- a/configure.ac
+++ b/configure.ac
@@ -9,7 +9,7 @@
 	CXXFLAGS="-O2 -Wall -W -fno-strength-reduce"
 fi
 
-AM_CONFIG_HEADER(config.h)
+AC_CONFIG_HEADERS(config.h)
 
 dnl Checks for programs.
 AC_PROG_CC
@@ -17,6 +17,7 @@
 AC_PROG_LN_S
 AC_PROG_INSTALL
 AC_PROG_RANLIB
+AM_PROG_AR
 
 dnl Checks for typedefs, structures, and compiler characteristics.
 AC_C_CONST
@@ -26,7 +27,7 @@
 AC_PROG_GCC_TRADITIONAL
 AC_CHECK_FUNCS(strdup strstr)
 
-AC_LANG_CPLUSPLUS
+AC_PROG_CXX
 
 #For FreeBSD, look in /usr/local/(lib,include) first, since ncurses4
 #must be installed as an add-on on these systems in /usr/local
@@ -233,55 +234,12 @@
 REQ_CURSES=1
 
 if test "$WANT_CURSES" = "1" ; then
-	AC_CHECK_LIB(curses,main,HAVE_LIBCURSES=1)
-	AC_CHECK_LIB(ncurses,main,HAVE_LIBNCURSES=1)
-	AC_CHECK_HEADER(curses.h,HAVE_CURSES_H=1,HAVE_CURSES_H=0)
-	AC_CHECK_HEADER(ncurses/ncurses.h,HAVE_NCURSES_NCURSES_H=1)
-	AC_CHECK_HEADER(ncurses/curses.h,HAVE_NCURSES_CURSES_H=1)
-	AC_CHECK_HEADER(ncurses.h,HAVE_NCURSES_H=1)
-
-	if test "$FORCECURSES" = "1" ; then
-		if test "$HAVE_LIBCURSES" = 0 -o "$HAVE_CURSES_H" = 0; then
-			AC_MSG_ERROR([you forced using curses instead of ncurses, but lib/include cannot be found])
-		fi
-		AC_DEFINE_UNQUOTED(NCURSES_HEADER, [<curses.h>],
-			[Which headerfile to include for ncurses support])
-		NCURSES_LIBS="-lcurses"
-		AC_SUBST(NCURSES_LIBS)
-	else
-		HAVE_CURSES="yes"
-		if test "$HAVE_LIBNCURSES" = 1 ; then
-			NCURSES_LIBS="-lncurses"
-		elif test "$HAVE_LIBCURSES" = 1 ; then
-			NCURSES_LIBS="-lcurses"
-		else
-			HAVE_CURSES="no"
-		fi
-
-		#header(s) found?
-		HAVE_CURSES_HEADER=1
-		if test "$HAVE_NCURSES_NCURSES_H" = "1" ; then
-			NCURSES_HEADER="<ncurses/ncurses.h>"
-		elif test "$HAVE_NCURSES_CURSES_H" = "1" ; then
-			NCURSES_HEADER="<ncurses/curses.h>"
-		elif test "$HAVE_NCURSES_H" = "1" ; then
-			NCURSES_HEADER="<ncurses.h>"
-		elif test "$HAVE_CURSES_H" = "1" ; then
-			NCURSES_HEADER="<curses.h>"
-		else
-			HAVE_CURSES_HEADER=0
-		fi
-
-		if test "$HAVE_CURSES_HEADER" = "0" ; then HAVE_CURSES="no" ; fi
-
-		if test "$HAVE_CURSES" = "yes" ; then
-			AC_SUBST(NCURSES_LIBS)
-			AC_DEFINE_UNQUOTED(NCURSES_HEADER, $NCURSES_HEADER,
-				[Which headerfile to include for ncurses support])
-		elif test "$REQ_CURSES" = "1" ; then
-			AC_MSG_ERROR([could not find (n)curses libs or includes, which are required])
-		fi
-	fi #FORCECURSES
+	PKG_CHECK_MODULES([NCURSES], [ncurses])
+	HAVE_CURSES="yes"
+	HAVE_CURSES_HEADER=1
+	NCURSES_HEADER="<ncurses.h>"
+	AC_DEFINE_UNQUOTED(NCURSES_HEADER, $NCURSES_HEADER,
+		[Which headerfile to include for ncurses support])
 fi
 
 #Sound output devices.