verify: show progress while verifying dirlogs In repos with treemanifests, the non-root-directory dirlogs often have many more total revisions than the root manifest log has. This change adds progress out to that part of 'hg verify'. Since the verification is recursive along the directory tree, we don't know how many total revisions there are at the beginning of the command, so instead we report progress in units of directories, much like we report progress for verification of files today. I'm not very happy with passing both 'storefiles' and 'progress' into the recursive calls. I tried passing in just a 'visitdir(dir)' callback, but the results did not seem better overall. I'm happy to update if anyone has better ideas.