obshistory: give a more correct name to a variable This variable holds a list of predecessors, which obslog presents to graphmod as parents so the latter could understand the data without the need to introduce another graph edge type specifically for predecessors. Also remove debug comments.

tests: unindent lines that only have one leading space One space is not even defined in our .t files syntax.

rewind: make __rewind-hash__ extra field be bytes

touch: make __touch-noise__ extra field be bytes