[gnome-taquin] Improve a bit UI and CSS files.

[Arnaud B. <arnaudb src gnome org>]

commit 1b2b6cdd19886d833af08c80c19dd776dfc7dd9a
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Wed Jan 16 21:43:32 2019 +0100

    Improve a bit UI and CSS files.
    
    Add license headers, add missing requires
    tag and remove a gettext domain in a file
    that is designed to be used as a library.

 data/game-headerbar.ui | 20 ++++++++++++++++++--
 data/taquin-screens.ui | 16 ++++++++++++++++
 data/taquin.css        | 35 +++++++++++++++++------------------
 3 files changed, 51 insertions(+), 20 deletions(-)
---
diff --git a/data/game-headerbar.ui b/data/game-headerbar.ui
index 09975fd..f9b2076 100644
--- a/data/game-headerbar.ui
+++ b/data/game-headerbar.ui
@@ -1,6 +1,22 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<interface domain="gnome-taquin">
-  <!-- interface-requires gtk+ 3.0 -->
+<!--
+  This file is part of GNOME Taquin
+
+  GNOME Taquin 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 3 of the License, or
+  (at your option) any later version.
+
+  GNOME Taquin 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 GNOME Taquin.  If not, see <https://www.gnu.org/licenses/>.
+-->
+<interface>
+  <requires lib="gtk+" version="3.12"/>
   <menu id="window-menu">
     <section>
       <item>
diff --git a/data/taquin-screens.ui b/data/taquin-screens.ui
index adb7da9..935c015 100644
--- a/data/taquin-screens.ui
+++ b/data/taquin-screens.ui
@@ -1,4 +1,20 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+  This file is part of GNOME Taquin
+
+  GNOME Taquin 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 3 of the License, or
+  (at your option) any later version.
+
+  GNOME Taquin 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 GNOME Taquin.  If not, see <https://www.gnu.org/licenses/>.
+-->
 <interface>
   <requires lib="gtk+" version="3.12"/>
   <menu id="size-menu"><!-- TODO 3/4/5 accels? -->
diff --git a/data/taquin.css b/data/taquin.css
index 6e333a2..36f80c3 100644
--- a/data/taquin.css
+++ b/data/taquin.css
@@ -1,20 +1,19 @@
-/* Copyright (C) 2015-2016 Arnaud Bonatti <arnaud bonatti gmail com>
- *
- * This file is part of GNOME Taquin.
- *
- * GNOME Taquin 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 3 of the License, or
- * (at your option) any later version.
- *
- * GNOME Taquin 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 this application. If not, see <http://www.gnu.org/licenses/>.
- */
+/*
+  This file is part of GNOME Taquin
+
+  GNOME Taquin 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 3 of the License, or
+  (at your option) any later version.
+
+  GNOME Taquin 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 GNOME Taquin.  If not, see <https://www.gnu.org/licenses/>.
+*/
 
 /* GtkXyz is pre-3.19.n */
 
@@ -67,4 +66,4 @@ button.menubutton-like-combo:checked:backdrop,
 button.menubutton-like-combo:hover:backdrop {
     color:@theme_unfocused_fg_color;
     background:-gtk-gradient (radial, center center, 0, center center, 0.5, from(rgba (255, 255, 255, 0.3)), 
to(rgba (255, 255, 255, 0)));
-}
\ No newline at end of file
+}