make send_now check that the printer is online before talking to it

printcore.py

@@ -209,6 +209,7 @@ class printcore():
     def send_now(self,command):
         """Sends a command to the printer ahead of the command queue, without a checksum
         """
+        if(self.online):
             if(self.printing):
                 self.priqueue+=[command]
             else:
@@ -216,6 +217,8 @@ class printcore():
                     time.sleep(0.001)
                 self._send(command)
             #callback for command sent
+        else
+            print "Not connected to printer."
         
     def _print(self):
         #callback for printing started