avfilter/vf_hqdn3d.h: restore author attribution, history and project name

See git blame of pre split avfilter/vf_hqdn3d.c
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavfilter/vf_hqdn3d.h

 /*
- * This file is part of Libav.
+ * Copyright (c) 2003 Daniel Moreno <comac AT comac DOT darktech DOT org>
+ * Copyright (c) 2010 Baptiste Coudurier
+ * Copyright (c) 2012 Loren Merritt
  *
- * Libav is free software; you can redistribute it and/or modify
+ * This file is part of FFmpeg, ported from MPlayer.
+ *
+ * FFmpeg 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.
  *
- * Libav is distributed in the hope that it will be useful,
+ * FFmpeg 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 Libav; if not, write to the Free Software Foundation, Inc.,
+ * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */