D933: scmutil: add a new function to show changes after a command

[pulkit (Pulkit Goyal)]

pulkit added subscribers: yuja, quark.
pulkit added a comment.


  @quark I was unable to make 'hashchanges' resolved by templater. I took help from Yuya and he was bit confused on how you want it to be done. (adding @yuja)

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D933

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