shelve: new keep option

Does nothing yet. The docstring describes what it will soon be doing.

hgext/shelve.py

@@ -1055,6 +1055,8 b' def _dounshelve(ui, repo, *shelved, **op'
            _('delete the named shelved change(s)')),
           ('e', 'edit', False,
            _('invoke editor on commit messages')),
+          ('k', 'keep', False,
+           _('shelve, but keep changes in the working directory')),
           ('l', 'list', None,
            _('list current shelves')),
           ('m', 'message', '',

tests/test-shelve.t

@@ -76,6 +76,7 b' shelve has a help message'
       --date DATE           shelve with the specified commit date
    -d --delete              delete the named shelved change(s)
    -e --edit                invoke editor on commit messages
+   -k --keep                shelve, but keep changes in the working directory
    -l --list                list current shelves
    -m --message TEXT        use text as shelve message
    -n --name NAME           use the given name for the shelved commit