Merge branch 'pw/add-p-hunk-splitting-fix'
Marking a hunk 'selected' in "git add -p" and then splitting made
all the split pieces 'selected'; this has been changed to make them
all 'undecided', which gives better end-user experience.
* pw/add-p-hunk-splitting-fix:
add-patch: update hunk splitability after editing
add -p: mark split hunks as undecided