Mark as "internal but installed" the avio.h file.

This should prevent its direct inclusion in an external project, which
results broken if avformat.h is not included before.

Originally committed as revision 17626 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/avformat.h

@@ -23,7 +23,7 @@
 
 #define LIBAVFORMAT_VERSION_MAJOR 52
 #define LIBAVFORMAT_VERSION_MINOR 30
-#define LIBAVFORMAT_VERSION_MICRO  0
+#define LIBAVFORMAT_VERSION_MICRO  1
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
                                                LIBAVFORMAT_VERSION_MINOR, \

libavformat/avio.h

@@ -23,6 +23,9 @@
 /**
  * @file libavformat/avio.h
  * unbuffered I/O operations
+ *
+ * @warning This file has to be considered an internal but installed
+ * header, so it should not be directly included in your projects.
  */
 
 #include <stdint.h>