Use more inclusive copyright header

gui/app.js

@@ -1,4 +1,4 @@
-// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// Copyright (C) 2014 The Syncthing Authors.
 //
 // This program 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

gui/index.html

@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <!--
-// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// Copyright (C) 2014 The Syncthing Authors.
 //
 // This program 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

gui/modal.html

@@ -1,6 +1,6 @@
 <div class="modal fade" tabindex="-1" ng-attr-data-backdrop="{{ close ? true : 'static' }}" ng-attr-data-keyboard="{{ Boolean(close) }}">
   <!--
-  // Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+  // Copyright (C) 2014 The Syncthing Authors.
   //
   // This program 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

gui/overrides.css

@@ -1,5 +1,5 @@
 /*
-// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// Copyright (C) 2014 The Syncthing Authors.
 //
 // This program 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