Auto-reload config file on RENAME
Some editors (like Vim), create a temp file when saving, then replace
the file being edited with the temp file. This causes the FS notify
event to be RENAME, not WRITE, so auto-reload misses this.
In addition to that, the file is removed from the watcher and the
auto-reload functionality stops working entirely after the first RENAME.
https://github.com/fsnotify/fsnotify/issues/255 describes this.