add some python example for tcp server and client.

examples/network/tcp_client.py

@@ -0,0 +1,16 @@
+# -*- coding: utf-8 -*-
+
+import socket
+
+s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
+
+s.connect(('192.168.10.110',6001))
+
+print s.recv(1024)
+
+for data in ['rtt_nano','rtt_thread','rtt_bsp']:
+    s.send(data)
+    print s.recv(1024)
+
+s.send('exit')
+s.close()