Subtree permissions

Issue Summary

As it goes this module is ok, if you have separate menus, but then having separate menus creates problems. Drupal and themes seem best with one menu which you can then split if you want primary and secondary. Merging menus seems complex, so best option I have come up with is multiple menu block inline so they look like one menu. Then this module works for restricting user edit access to one "submenu". However, it would be nicer and easier if this module allowed subtree permissions rather than just the whole menu.