Merge branch 'pw/rebase-cleanup-merge-strategy-option-handling'

Clean-up of the code path that deals with merge strategy option handling in "git rebase". * pw/rebase-cleanup-merge-strategy-option-handling: rebase: remove a couple of redundant strategy tests rebase -m: fix serialization of strategy options rebase -m: cleanup --strategy-option handling sequencer: use struct strvec to store merge strategy options rebase: stop reading and writing unnecessary strategy state