Update CentralAuth for 1.24wmf17 cherry-picks

* Pass normalized username to GlobalRenameUserStatus
  (I5b75ecb41e8697f975963729df463225212a54f6)
* Wrap CentralAuthUser::attach in an explicit transaction
  (I715c3e2b77ba28efc36a375ee214021f1334a1d1)

Change-Id: I7746cfe545de4f245b9951b9a3ef52df932df024
Merge "Update CentralAuth for 1.24wmf17 cherry-picks" into wmf/1.24wmf17