contrib/rpc_examples: Add (dis)connect methods

Add these methods such that the OpenOcd class can also be used outside
of a 'with' statement.

Change-Id: I927c93fff2dc05cc74daa56360a7262e736a639f
Signed-off-by: Marc Schink <openocd-dev@marcschink.de>
Reviewed-on: http://openocd.zylin.com/5189
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>

contrib/rpc_examples/ocd_rpc_example.py

@@ -49,10 +49,16 @@ class OpenOcd:
         self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 
     def __enter__(self):
-        self.sock.connect((self.tclRpcIp, self.tclRpcPort))
+        self.connect()
         return self
 
     def __exit__(self, type, value, traceback):
+        self.disconnect()
+
+    def connect(self):
+        self.sock.connect((self.tclRpcIp, self.tclRpcPort))
+
+    def disconnect(self):
         try:
             self.send("exit")
         finally: