Change API. Indeed, currently wired communications

are aborted when receiver node turned off. This
may not be desire when implementing UDP communications.
Now user can use a boolean when using send()/sendt() to change this
behavior.

tests/api_send_eth0_1s1r/out

@@ -7,5 +7,9 @@
 [t=3.000,src=n1] Received: Hello World!
 [t=3.000,src=n1] Turned off
 [t=4.000,src=n1] Turned on
+[t=4.000,src=n0] Send 10 bytes to n1 on eth0
 [t=5.000,src=n1] Receive failed code=-1
-[t=5.000,src=esds] Simulation ends
+[t=5.000,src=n1] Turned off
+[t=6.000,src=n1] Turned on
+[t=7.000,src=n1] Receive failed code=-1
+[t=14.000,src=esds] Simulation ends

tests/api_send_eth0_1s1r/receiver.py

@@ -17,4 +17,10 @@ def execute(api):
     code, data=api.receivet("eth0",1)
     msg="Received: "+data if code == 0 else "Receive failed code="+str(code)
     api.log(msg)
-    
+    ##### Ensure data is not receive turned off but communication is not cancel
+    api.turn_off()
+    api.wait(1)
+    api.turn_on()
+    code, data=api.receivet("eth0",1)
+    msg="Received: "+data if code == 0 else "Receive failed code="+str(code)
+    api.log(msg)

tests/api_send_eth0_1s1r/sender.py

@@ -5,3 +5,4 @@ def execute(api):
     api.send("eth0","Hello World!",1,1)
     api.wait(1) # Goto 3 seconds
     api.send("eth0","Hello World!",1,1)
+    api.send("eth0","Hello World!",10,1,False) # Now communication should not be aborted even if receiver turned_off (e.g UDP)