Hotwatch doesn't detect changes to file which are done while the handler callback is active

[hoerman]

Hotwatch doesn't seem to detect changes done to files, which are done while a watch callback is running

let mut watch = Hotwatch::new().unwrap();

watch.watch("/tmp/test123", |e| {
    println!("{:?}", e);
    std::thread::sleep(Duration::from_secs(10));
}).unwrap();

Run this code an do an "echo >> /tmp/test123" once, and than a second time short after the debug printout appears. Hotwatch will only detect the first change to the file. The same happens with the blocking Variant of the module. Tested with Linux.

The behavior results in some possible race conditions, when one want's to be sure to always use the latest revision of the given file. At least this behavior should be noted in the module documentation.