Implements the func #7 #8 sending udp of client ,receiving udp of AP
	modified:   AndroidManifest.xml
    Add the permission: Internet Access for socket communication
	modified:   src/com/ukipedia/wifitether/MainActivity.java
	new file:   src/com/ukipedia/wifitether/UdpReceiveThread.java
    #7 I implemented
  new file:   src/com/ukipedia/wifitether/UdpSendThread.java
    #8 I must implement the function sending udp packet as thread
       because if I didn't , I would encounter the Exception like
       this:" Can't connect the socket in MainThread "
	new file:   src/com/ukipedia/wifitether/WifiTetherConstants.java
    Create the management of Constants