* check the wgPostEditConfirmationDisabled mw.config flag
  (to be introduced in Idff34615a48) and do not prepare a
  save success notification if set
* add a postEditMobile hook that works just like core's postEdit
  hook

Bug: T245790
Depends-On: Idff34615a48ffa81e6e49a3efb5c66bd8753586c
Change-Id: I130c9e2164da3985341040ef880dde800df62e4e