effectflag: split effect flag meta
Split effect flag meta into 3 separate flags:
- USERCHANGED
- DATECHANGED
- BRANCHCHANGED
Also display them separately for the moment, they could be grouped back
together if we want later.
#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