Fix bug in previous primitive-undo changes
Remove unnecessary code in record_point skipping marker adjustments
Fix comment
Revert del-pos in undo-make-selective-list, change doc of undo-elt-in-region
More of previous change
Implement marker skipping in undo-make-selective-list
Add TODO in undo-tests.el
Tweak undo-make-selective-list change
Tweak comment in del_range_2
Add TODO to validate marker adjustment against current buffer