Added copyright to IFileSystemManager.java

core/src/cz/nic/tablexia/util/IFileSystemManager.java

+/*
+ * Copyright (C) 2017 CZ.NIC, z.s.p.o. (http://www.nic.cz/)
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 package cz.nic.tablexia.util;
 
 /**