D3668: graft: add a new `--stop` flag to stop interrupted graft

[pulkit (Pulkit Goyal)]

pulkit added a comment.


  In https://phab.mercurial-scm.org/D3668#58070, @yuja wrote:
  
  > >   The `--stop` flag takes back you to the last successful step i.e. it will keep
  > >   your grafted commits, it will just clear the mergestate and interrupted graft
  > >   state.
  >
  > No idea if git is right regarding UI, but they appear to have `--quit` for
  >  this.
  >
  > https://git-scm.com/docs/git-cherry-pick
  
  
  I asked people on IRC, nbjoerg and one more said '--stop' is better. However I am fine with changing that to `--quit`
  
  > The code looks good to me. We'll need to update `cmdutil.unfinishedstates`
  >  as well.
  
  Will do. I was also thinking to add a new general help topic which will document about `--continue`, `--abort` and `--stop` flags and point them as help text or "help text of help text" there.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D3668

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