effectflag: activate effect flag on test-evolve-obshistory-complex.t test file
Prepare activation of effect flag by default by activating it on test-evolve-
obshistory-complex.t test file first.
#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 'set:(**.py or grep("^#!.*python")) - removed()' 2>/dev/null \
> | xargs pyflakes 2>/dev/null