graft: store user passed date and user information in graftstate Right now, `hg help graft` says: The -c/--continue option does not reapply earlier options, except for --force. which should be treated as a bug. A good user experience is that the commands remember the arguments passed initially and preserve them during `hg graft --continue`. This patch starts storing the user and date information in graftstate if user passed it. Upcoming patches will make sure we preserve that information during --continue and them don't allow user to pass any new arguments with --continue. I don't think there is any another `--continue` flag which allows new options to be passed with it. Differential Revision: https://phab.mercurial-scm.org/D3657