autoconf: Add --without-flac option

configure.ac

@@ -137,15 +137,6 @@ else
         AM_CONDITIONAL([USE_WIN32], false)
 fi
 
-dnl FLAC stuff
-AC_CHECK_HEADER(FLAC/stream_decoder.h, libflac_found=yes, libflac_found=no)
-if test x"$libflac_found" = "xyes"; then
-		AM_CONDITIONAL([USE_FLAC], true)
-		CFLAGS=""
-		LIBS="$LIBS -lFLAC"
-else
-		AM_CONDITIONAL([USE_FLAC], false)
-fi
 
 dnl Wii crap
 AC_CHECK_LIB(ogc, IOS_ReloadIOS, libogc_found=yes, libogc_found=no, [-mrvl -L${DEVKITPRO}/libogc/lib/wii])
@@ -310,6 +301,11 @@ AC_ARG_ENABLE(fortify-source,
         ADD_FORTIFY=$enableval,
         ADD_FORTIFY=no)
 
+AC_ARG_WITH([flac],
+		[AS_HELP_STRING([--without-flac],[Build without FLAC support @<:@default=no@:>@])],
+		[],
+		[with_flac=yes])
+
 dnl fortify needs -O; do this early so ADD_OPT can override with higher -O level
 if test x$ADD_FORTIFY \!= xno; then
         CFLAGS="$CFLAGS -O -D_FORTIFY_SOURCE=2"
@@ -330,6 +326,14 @@ if test x$ADD_LUDICROUS \!= xno; then
         CFLAGS="$CFLAGS -Werror"
 fi
 
+AM_CONDITIONAL([USE_FLAC], false)
+if test "x$with_flac" = "xyes"; then
+		AC_CHECK_HEADER(FLAC/stream_decoder.h, libflac_found=yes, libflac_found=no)
+		if test x"$libflac_found" = "xyes"; then
+				AM_CONDITIONAL([USE_FLAC], true)
+		fi
+fi
+
 dnl ... but put the warnings first, to make it possible to quiet certain
 dnl warnings if necessary, while still providing most of the benefit
 if test x$ADD_WARN \!= xno; then