add --sse-os argument, remove -ffast-math from gcc CFLAGS

configure.in

@@ -64,6 +64,18 @@ AC_ARG_ENABLE(debug,
 esac],[debug=false])
 AM_CONDITIONAL(DEBUG, test x$debug = xtrue)
 
+AC_ARG_ENABLE(sse_os,
+[  --sse-os                 Enable SSE support by asserting that the OS supports SSE instructions],
+[case "${enableval}" in
+	yes) sse_os=true ;;
+	no)  sse_os=false ;;
+	*) AC_MSG_ERROR(bad value ${enableval} for --sse-os) ;;
+esac],[sse_os=false])
+AM_CONDITIONAL(FLaC__SSE_OS, test x$sse_os = xtrue)
+if test x$sse_os = xtrue ; then
+AC_DEFINE(FLAC__SSE_OS)
+fi
+
 AM_PATH_XMMS(0.9.5.1, , AC_MSG_WARN([*** XMMS >= 0.9.5.1 not installed - xmms support will not be built]))
 AM_CONDITIONAL(FLaC__HAS_XMMS, test x$XMMS_INPUT_PLUGIN_DIR != x)
 
@@ -129,7 +141,7 @@ CFLAGS="$CFLAGS -g -O0 -DDEBUG"
 else
 CFLAGS="$CFLAGS -O3 -DNDEBUG"
 	if test x$GCC = xyes; then
-		CFLAGS="$CFLAGS -fomit-frame-pointer -funroll-loops -ffast-math -finline-functions"
+		CFLAGS="$CFLAGS -fomit-frame-pointer -funroll-loops -finline-functions"
 	fi
 fi