Merge branch 'bc/gpg-sign-everywhere'

Teach "--gpg-sign" option to many commands that create commits. * bc/gpg-sign-everywhere: pull: add the --gpg-sign option. rebase: add the --gpg-sign option rebase: parse options in stuck-long mode rebase: don't try to match -M option rebase: remove useless arguments check am: add the --gpg-sign option am: parse options in stuck-long mode git-sh-setup.sh: add variable to use the stuck-long mode cherry-pick, revert: add the --gpg-sign option