lavfi : change xBR filter to LGPL

Hyllian's message : "Hi, Put lgpl on this and use it as you wish. It's free!"
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

LICENSE.md

@@ -49,7 +49,6 @@ Specifically, the GPL parts of FFmpeg are:
     - vf_stereo3d.c
     - vf_super2xsai.c
     - vf_tinterlace.c
-    - vf_xbr.c
     - vsrc_mptestsrc.c
 
 Should you, for whatever reason, prefer to use version 3 of the (L)GPL, then

configure

@@ -2608,7 +2608,6 @@ vidstabtransform_filter_deps="libvidstab"
 pixfmts_super2xsai_test_deps="super2xsai_filter"
 tinterlace_merge_test_deps="tinterlace_filter"
 tinterlace_pad_test_deps="tinterlace_filter"
-xbr_filter_deps="gpl"
 zmq_filter_deps="libzmq"
 zoompan_filter_deps="swscale"
 

libavfilter/vf_xbr.c

@@ -5,19 +5,23 @@
  *
  * Copyright (c) 2014 Arwa Arif <arwaarif1994@gmail.com>
  *
- * 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.
+ * Changed from GPL to LGPL, in accordance with Hyllian's message:
+ *     On Tue, Nov 11, 2014 at 11:52 PM, Sérgio <sergiogdb@gmail.com> wrote:
+ *         > Hi, Put lgpl on this and use it as you wish. It's free!
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
  *
  * 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.
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
  *
- * You should have received a copy of the GNU General Public License along
- * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**