Arg Watcher

--watcher

There are different backends used to determine when a file has changed.

• poll (default) --- Checks for file modifications by scanning the filesystem every second.
• native --- Uses the native operating system facilities to receive notifications when files change. This can have less constant overhead, but may not be as reliable as the poll based watcher. See these issues for more information: #383 #1441 #1707 #2035 #2102