It’s been a very frustrating January transfer window for Celtic fans who have been crying out for serious business to be done across the month. Fans have been left exasperated at the lack of signings and that feeling of discontent only increased right up until the deadline on Thursday night. Here are the Bhoys’ confirmed deals on deadline day right up until the window closed at 11.30pm. We’ve also listed the club’s overall transfer activity in January with Celtic now looking to retain their Scottish Premiership and Scottish Cup titles in the second-half of the season. Celtic transfer incomings…