dirstate.status: if a file is marked as copied, consider it modified
After a "hg copy --force --after somefile cleanfile", cleanfile
shouldn't be considered clean anymore.
adding dir/bar
adding foo
dir/bar
foo
adding dir/bar_2
adding foo_2
dir/bar_2
foo_2
adding a
adding c
adding b
adding d
removing a
removing c
recording removal of a as rename to b (100% similar)