correctly record file-level history when the local side renames a directory

Fix theoretical issue in filecommit. If the file was copied, we don't want to reuse the original entry. I think this is mostly a theoretical issue - when there are copies, fp1 == nullid, so it's very unlikely that the fl.cmp(fp1, t) would think the file was unmodified. In any case, if there was a copy, we should forcefully create a new entry.