Add an automated tool that does basic checking of includes sort order.
Fix more header sorting issues in Common/ (now check-includes clean).
Fix more header sorting issues in DiscIO/ (now check-includes clean).
Fix more header sorting issues in AudioCommon/ (now check-includes clean).
Fix more header sorting issues in InputCommon/ (now check-includes clean).
Fix more header sorting issues in VideoCommon/ (now check-includes clean).
Fix more header sorting issues in DolphinWX/ (now check-includes clean).