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.
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)