libmpcodecs/av_helpers: update to latest version from mplayer

Please see mplayer svn for authorship and individual commits
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavfilter/libmpcodecs/av_helpers.h

+/*
+ * Generic libav* helpers
+ *
+ * This file is part of MPlayer.
+ *
+ * MPlayer is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * MPlayer is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with MPlayer; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPLAYER_AV_HELPERS_H
+#define MPLAYER_AV_HELPERS_H
+
+void ff_init_avcodec(void);
+void ff_init_avformat(void);
+
+#endif /* MPLAYER_AV_HELPERS_H */