Fix release note to introduce agent auto update
* Server mode agent
* Legacy nGrinder agents must be accessible to nGrinder controller via TCP, it was difficult to set up a private agents to connect to the controller behind a firewall. Now, nGrinder provides the server mode agent. You can easily connect the private agent to the nGrinder controller behind a firewall with the server mode agent.
* See https://github.com/donggyu04/ngrinder/wiki/Server-Mode-Agent
+ * Agent auto update
+ * When the test is executed with older version of agent, it triggers agent auto update.
* GitHub script storage
* nGrinder is a SVN server itself to manage test scripts. SVN is very suitable for nGrinder, but it is an old technology. So, we added github as another script storage.
* See https://github.com/donggyu04/ngrinder/wiki/GitHub-script-storage
