Globally rename the header inclusion guard names.

Consistently apply this rule: the guard name is obtained from the
filename by stripping the leading "lib", converting '/' and '.'  to
'_' and uppercasing the resulting name. Guard names in the root
directory have to be prefixed by "FFMPEG_".

Originally committed as revision 15120 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/mpeg4audio.h

@@ -19,8 +19,8 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#ifndef FFMPEG_MPEG4AUDIO_H
-#define FFMPEG_MPEG4AUDIO_H
+#ifndef AVCODEC_MPEG4AUDIO_H
+#define AVCODEC_MPEG4AUDIO_H
 
 #include <stdint.h>
 
@@ -46,4 +46,4 @@ extern const uint8_t ff_mpeg4audio_channels[8];
  */
 int ff_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf, int buf_size);
 
-#endif /* FFMPEG_MPEGAUDIO_H */
+#endif /* AVCODEC_MPEG4AUDIO_H */