lavu: bump major to 52

In addition to the recent tables mess, the AVOption defaults behavior
changed, so an old lavc used with a new lavu will get completely messed
up defaults.

doc/APIchanges

@@ -8,7 +8,7 @@ libavfilter:   2012-06-22
 libavformat:   2012-01-27
 libavresample: 2012-10-05
 libswscale:    2011-06-20
-libavutil:     2011-04-18
+libavutil:     2012-10-22
 
 
 API changes, most recent first:

libavutil/version.h

@@ -36,8 +36,8 @@
  * @{
  */
 
-#define LIBAVUTIL_VERSION_MAJOR 51
-#define LIBAVUTIL_VERSION_MINOR 45
+#define LIBAVUTIL_VERSION_MAJOR 52
+#define LIBAVUTIL_VERSION_MINOR  0
 #define LIBAVUTIL_VERSION_MICRO  0
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \