License stuff and the like, namely:

Replacement of reference to now defunct http://www.iacons.net by one to https://github.com/softius
Clarification that license is GPL 3.
Reference to (i.e. application of) the GPL according to the FSF's recommendations

Author: penpendede

proxy.php

@@ -2,9 +2,18 @@
 
 /**
  * AJAX Cross Domain (PHP) Proxy 0.8
- *    by Iacovos Constantinou (http://www.iacons.net)
+ * Coypright (C) 2016 Iacovos Constantinou (https://github.com/softius)
  *
- * Released under CC-GNU GPL
+ * 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/>.
  */
 
 /**