evolve: stop passing no-op "progresscb" into continueevolve()
The "progresscb" doesn't do anything in the --continue case, so
there's no need to pass it into continueevolve().
This lets us remove the --no-all that was added to the test as a
workaround.
#require test-repo pyflakes
Copied from Mercurial core (60ee2593a270)
$ cd "`dirname "$TESTDIR"`"
run pyflakes on all tracked files ending in .py or without a file ending
(skipping binary file random-seed)
$ hg locate -I 'set:(**.py or grep("^#!.*python")) - removed()' 2>/dev/null \
> | xargs pyflakes 2>/dev/null