Merge branch 'jk/tree-name-and-depth-limit'

We now limit depth of the tree objects and maximum length of pathnames recorded in tree objects. * jk/tree-name-and-depth-limit: lower core.maxTreeDepth default to 2048 tree-diff: respect max_allowed_tree_depth list-objects: respect max_allowed_tree_depth read_tree(): respect max_allowed_tree_depth traverse_trees(): respect max_allowed_tree_depth add core.maxTreeDepth config fsck: detect very large tree pathnames tree-walk: rename "error" variable tree-walk: drop MAX_TRAVERSE_TREES macro tree-walk: reduce stack size for recursive functions