tests: fix doctest stability over Python versions
pprint ain't pretty in Python 2.4:
Changed in version 2.5: Dictionaries are sorted by key before the display is
computed; before 2.5, a dictionary was sorted only if its display required more
than one line, although that wasn’t documented.
Fixes issue introduced in
404feac78b8a.
convert: make toposort order stable when multiple orderings are possible
The output of some tests are changed. Not necessarily to the better, just other
valid permutations.
mq: stabilize update after strip of parent revision
Strip will (if it updates) update to the parent of revs[0], where revs are the
roots of the tree that is stripped.
When revs was list(set) it was thus undefined which root parent it would update
to. With sorted(set) it is at least stable what it updates to. (But it is very
possible that another more useful and predictable behaviour could be defined
... such as updating to the tip-most surviving wd ancestor.)