D3684: shelve: merge in obsshelve changes implemented at facebook

[lothiraldan (Boris Feld)]

lothiraldan added a comment.


  We just sent https://phab.mercurial-scm.org/D3685 that update shelve to not use rebase anymore.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D3684

To: durin42, #hg-reviewers
Cc: lothiraldan, mercurial-devel