D3901: histedit: add history-editing-backup config option

[khanchi97 (Sushil khanchi)]

khanchi97 added a comment.


  > Because this option has not been part of a release yet. There is no point of releasing a deprecated feature.
  
  Got it. Thanks!

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D3901

To: khanchi97, durin42, #hg-reviewers
Cc: pulkit, yuja, mercurial-devel