Added a basic WiFi UDP client example (#114)

* Added a basic WiFi UDP client example: a sketch that sends random bytes over udp.

* Updated udp example and included Python and Ruby UDP servers.

libraries/WiFi/examples/WiFiUDPClient/udp_server.py

@@ -0,0 +1,30 @@
+# This python script listens on UDP port 3333 
+# for messages from the ESP32 board and prints them
+import socket
+import sys
+
+try :
+    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+except socket.error, msg :
+    print 'Failed to create socket. Error Code : ' + str(msg[0]) + ' Message ' + msg[1]
+    sys.exit()
+
+try:
+    s.bind(('', 3333))
+except socket.error , msg:
+    print 'Bind failed. Error: ' + str(msg[0]) + ': ' + msg[1]
+    sys.exit()
+     
+print 'Server listening'
+
+while 1:
+    d = s.recvfrom(1024)
+    data = d[0]
+     
+    if not data: 
+        break
+    
+    print data.strip()
+    
+s.close()