localrepo: use "vfs.rename()" instead of "util.rename()" This patch makes "_journalfiles()" return a list of pairs of journal file and corresponded vfs instance instead of a list of journal files in full path, to use "vfs.rename()" instead of "util.rename()" in "aftertrans()". "undofiles()" still returns a list of undo files in full path, because "repair.strip()" expects such list. It'll be also made to return a list of pairs of undo file and corresponded vfs at vfs migration for "repair.strip()" in the near future.