[filter] Move header-line update to dired-filter--update
[filter] Fix bug with dired-subtree support removing directories that should be kept
[subtree] Refactor directory insertion
[subtree] Add a mechanism to preserve properties between reverts
[subtree] Add narrow
[subtree] get-ovs-in can default to "this subtree"
[subtree] Add subtree reverting
[subtree] Add local filters