gnome: add AUTHORS and COPYING

removed Sebastien Bourdelin as author of the video_widget.* code as it
has been completely re-written and doesn't behave like the version in the old client

Refs #69341

Change-Id: I48329b3b3718592059ab29c557ea1361b28a02b8

AUTHORS

+Current authors
+---------------
+
+Stepan Salenikovich <stepan dot salenikovich at savoirfairelinux dot com>
+Eloi BAIL <eloi dot bail at savoirfairelinux dot com>
+Guillaume Roguez <guillaume dot roguez at savoirfairelinux dot com>
+Emmanuel Lepage <emmanuel dot lepage at savoirfairelinux dot com>

src/video/video_widget.cpp

 /*
  *  Copyright (C) 2004-2015 Savoir-Faire Linux Inc.
- *  Author: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
  *  Author: Stepan Salenikovich <stepan.salenikovich@savoirfairelinux.com>
  *
  *  This program is free software; you can redistribute it and/or modify

src/video/video_widget.h

 /*
  *  Copyright (C) 2004-2015 Savoir-Faire Linux Inc.
- *  Author: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
  *  Author: Stepan Salenikovich <stepan.salenikovich@savoirfairelinux.com>
  *
  *  This program is free software; you can redistribute it and/or modify