Previously it depended on addFolder() / removeFolder() calls to adjust
watchers when new folders were added or removed. There also needed to be
complex move handling.
Now, any folder creation/move-in notifications automatically trigger
watcher additions and folder deletion/move-out triggers removal.
If a folder was renamed A -> B, the folder watcher for the inode
would be unaware and still report changes for A/foo. Now directory
renames in the watched folders are tracked and paths are updated
accordingly.
Christian Kamm