Added receive timestamp for each data record in XML output

mbus/mbus-protocol.h

@@ -83,6 +83,7 @@ typedef struct _mbus_frame {
     size_t data_size;
     
     int type;
+    time_t timestamp;
     
     //mbus_frame_data frame_data;
 
@@ -145,6 +146,8 @@ typedef struct _mbus_data_record {
     u_char data[234];
     size_t data_len;    
 
+    time_t timestamp;
+
     void *next;
 
 } mbus_data_record;