D3763: grep: add `--diff` flag

[yuja (Yuya Nishihara)]

yuja added a comment.


  Queued, thanks.
  
  Can you send a follow-up to deprecate the --all option?
  It doesn't make sense to provide both --all and --diff in user help.
  
  >   [('0', 'print0', None, _('end fields with NUL')),
  >   ('', 'all', None, _('print all revisions that match')),
  > 
  > +    ('', 'diff', None, _('print all revisions when the term was introduced or removed')),
  
  Next time, please make sure `test-check-*` pass.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D3763

To: sangeet259, #hg-reviewers
Cc: yuja, pulkit, mercurial-devel