Merge branch 'js/fsck-name-object'

When "git fsck" reports a broken link (e.g. a tree object contains a blob that does not exist), both containing object and the object that is referred to were reported with their 40-hex object names. The command learned the "--name-objects" option to show the path to the containing object from existing refs (e.g. "HEAD~24^2:file.txt"). * js/fsck-name-object: fsck: optionally show more helpful info for broken links fsck: give the error function a chance to see the fsck_options fsck_walk(): optionally name objects on the go fsck: refactor how to describe objects