shelve: directly handle `--continue`...
shelve: directly handle `--continue`
Shelve is currently sub-contracting some of its work to the rebase extension.
In order to make shelve more independent and flexible we would like shelve to
handle the parent alignment directly.
This changeset takes on the next step, handling the abort process. Same as for
--abort. It turns out we have all the necessary bits in the `shelvestate`
file. So we do not need anything from the interrupted rebase.
Differential Revision:
https://phab.mercurial-scm.org/D3689
