Bump version to 0.5.1.


Originally committed as revision 22146 to svn://svn.ffmpeg.org/ffmpeg/branches/0.5
diff --git a/VERSION b/VERSION
index 2eb3c4f..4b9fcbe 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5
+0.5.1