This branch for debugging DTLS #90, #150, #195, #227

The purpose of this branch is to share work in process.
Change sellect() of UDP to poll()
Rewrite UDP6 for DTLS6

Known bug: can't reconnect DTLS

Signed-off-by: tomoaki <tomoaki@tomy-tech.com>

MQTTSNGateway/src/linux/Network.h

@@ -80,6 +80,7 @@ public:
 	bool isValid(void);
 	bool isSecure(void);
 	int  getSock(void);
+    void setSecure(bool secureFlg);
 
 private:
 	static SSL_CTX* _ctx;