libvlc: dissociate the libvlc version from the libvlccore/VLC package version

The values should be about libvlc and nothing else.

include/vlc/libvlc_version.h.in

@@ -52,4 +52,28 @@
          LIBVLC_VERSION(LIBVLC_VERSION_MAJOR, LIBVLC_VERSION_MINOR, \
                         LIBVLC_VERSION_REVISION, LIBVLC_VERSION_EXTRA)
 
+
+/** LibVLC ABI major version number, updated when incompatible changes are added */
+# define LIBVLC_ABI_VERSION_MAJOR  (@LIBVLC_ABI_LT_CURRENT@ - @LIBVLC_ABI_LT_AGE@)
+
+/** LibVLC ABI minor version number, updated when compatible changes are added */
+# define LIBVLC_ABI_VERSION_MINOR  (@LIBVLC_ABI_LT_AGE@)
+
+/** LibVLC ABI micro version number, updated with new releases */
+# define LIBVLC_ABI_VERSION_MICRO  (@LIBVLC_ABI_LT_REVISION@)
+
+/** LibVLC full ABI version combining the major VLC version and the .so version:
+ * - A 0xFF000000 mask gives the VLC major version,
+ * - A 0x00FF0000 mask gives the LibVLC major ABI version,
+ * - A 0x0000FF00 mask gives the LibVLC minor ABI version,
+ * - A 0x000000FF mask gives the LibVLC ABI revision.
+ *
+ * LibVLC is considered compatible with your code if the VLC major and LibVLC
+ * major values are equal and the minor ABI version is equal or higher than the
+ * value you compiled with.
+ */
+# define LIBVLC_ABI_VERSION_INT \
+         LIBVLC_VERSION(LIBVLC_VERSION_MAJOR, LIBVLC_ABI_VERSION_MAJOR, \
+                        LIBVLC_ABI_VERSION_MINOR, LIBVLC_ABI_VERSION_MICRO )
+
 #endif