add support for timestamp in Message

The Message Object has now an parameter named timestamp which is set when
the message is received.
The reveiv Method returns the ID of the received message

CANLibrary/CanMessage.py

@@ -48,6 +48,7 @@ class CanMessage(object):
         self.Id = MessageId
         self.CycleTime = MessageCycleTime
         self.Label = Label
+        self.timestamp = 0
         
         # create an initial array of message data
         for i in range(0, self.Length):

CANLibrary/PCan.py

@@ -127,5 +127,7 @@ class PcanAdapter (object):
                             for i in range(0, self.Messages[msgKey].Length):
                                 self.Messages[msgKey].Data[i] = msg.DATA[i]
                             self.Messages[msgKey].decomposeData()
+                            self.Messages[msgKey].timestamp = timestamp.micros + 1000 * timestamp.millis + 0xFFFFFFFF * 1000 * timestamp.millis_overflow
+                            return msg.ID
             elif result == PCANBasic.PCAN_ERROR_QRCVEMPTY:
-                break
+                return None