* fs_unmount() freed vnodes, but didn't remove them from the unused list if
needed.
* vfs_get_module_path() could put a vnode twice under several situations.
* vnode_path_to_vnode() now always puts the dir vnode, even if the provided
path is NULL. Documented the fact that it does eat the ref, too.
* Added a to-do item in vfs_get_vnode_cache() about a possible problem.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16662 a95241bf-73f2-0310-859d-f6bbb57e9c96