lib*/version: Move library version functions into files of their own

This avoids having to rebuild big files every time FFMPEG_VERSION
changes (which it does with every commit).

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libswresample/version.c

@@ -0,0 +1,45 @@
+/*
+ * Version functions.
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "config.h"
+#include "libavutil/avassert.h"
+#include "swresample.h"
+#include "version.h"
+
+#include "libavutil/ffversion.h"
+const char swr_ffversion[] = "FFmpeg version " FFMPEG_VERSION;
+
+unsigned swresample_version(void)
+{
+    av_assert0(LIBSWRESAMPLE_VERSION_MICRO >= 100);
+    return LIBSWRESAMPLE_VERSION_INT;
+}
+
+const char *swresample_configuration(void)
+{
+    return FFMPEG_CONFIGURATION;
+}
+
+const char *swresample_license(void)
+{
+#define LICENSE_PREFIX "libswresample license: "
+    return &LICENSE_PREFIX FFMPEG_LICENSE[sizeof(LICENSE_PREFIX) - 1];
+}
+