Merge branch 'sh/rebase-i-p'

* sh/rebase-i-p: git-rebase--interactive.sh: comparision with == is bashism rebase-i-p: minimum fix to obvious issues rebase-i-p: if todo was reordered use HEAD as the rewritten parent rebase-i-p: do not include non-first-parent commits touching UPSTREAM rebase-i-p: only list commits that require rewriting in todo rebase-i-p: fix 'no squashing merges' tripping up non-merges rebase-i-p: delay saving current-commit to REWRITTEN if squashing rebase-i-p: use HEAD for updating the ref instead of mapping OLDHEAD rebase-i-p: test to exclude commits from todo based on its parents