license change to allow linking with non-GPLv3 FOSS software

LICENSE

@@ -1,3 +1,28 @@
+Copyright (C) 2015-2017 Sebastian Herbord
+
+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 Software Foundation; either version 3 of the License, or (at your option) any later version.
+
+This program 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.
+
+Please find a copy of the of the GNU General Public License at the end of this file or see <http://www.gnu.org/licenses>.
+
+Additional permissions are granted under GNU GPL version 3 section 7 to Free and Open Source Software ("FOSS") without requiring that such software is covered by the GPLv3.
+
+  1. Permission to link with the usvfs_x64.dll and/or usvfs_x86.dll
+
+  2. Permission to distribute unmodified binary copies of the usvfs library
+
+Theses permissions (and no other) are granted provided that the software:
+
+  1. Is distributed under a license that satisfies the Free Software Definition (https://www.gnu.org/philosophy/free-sw.en.html) or the Open Source Definition Version (https://opensource.org/osd)
+
+  2. Includes the copyright notice "usvfs - User-Space Virtual File System, Copyright (C) Sebastian Herbord", a copy of this license and a link to the usvfs repository in its user-interface and any user-facing documentation.
+
+  3. Is not linked or distributed with proprietary (non-FOSS) software.
+
+
+-------------------------------------------------------------------------
+
                     GNU GENERAL PUBLIC LICENSE
                        Version 3, 29 June 2007