move elastix to non-free.md:

elastix 3.0 is based on proprietary 3CX
Previous version 2.5 was based on Asterisk and is unmaintained
https://www.elastix.org/downloads/
fixes #1017

README.md

@@ -337,7 +337,6 @@ _[SIP](https://en.wikipedia.org/wiki/Session_Initiation_Protocol) telephony soft
 
 _[IPBX](https://en.wikipedia.org/wiki/IP_PBX) telephony software_
 
-  * [Elastix](http://www.elastix.org) - Unified communications server software based on Asterisk. ([Source Code](https://svn.code.sf.net/p/elastix/code/trunk/)) `GPLv2` `PHP`
   * [Freepbx](http://www.freepbx.org) - Web-based open source GUI that controls and manages Asterisk. ([Source Code](http://git.freepbx.org/projects/FREEPBX)) `GPLv2` `PHP`
   * [Kazoo](http://2600hz.org/) - KAZOO is an open-source, highly scalable software platform designed to provide carrier-grade VoIP switch functions and features. ([Source Code](https://github.com/2600hz/KAZOO)) `MPLv1.1` `Erlang`
 

non-free.md

@@ -50,6 +50,10 @@
   * [Cubiks-2048](https://github.com/Kshitij-Banerjee/Cubiks-2048) - Clone of 2048 game in 3D. ([Demo](https://kshitij-banerjee.github.io/Cubiks-2048/)) `CCBYNCv4` `HTML5`
   * [untrusted](https://github.com/AlexNisnevich/untrusted) - Untrusted is a unique puzzle game designed for geeks and developers, where you solve the puzzles in the game by reading and writing Javascript. ([Demo](http://alex.nisnevich.com/untrusted/)) `CCBYNCSAv3/Custom` `Nodejs`
 
+## IPBX
+
+  * [Elastix](http://www.elastix.org) `⊘ Proprietary` - Unified communications server software based on 3CX. ([Source Code](https://svn.code.sf.net/p/elastix/code/trunk/)) `GPLv2` `PHP`
+
 
 ## Media Streaming