all: Add filesystem notification support

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3986

vendor/github.com/zillode/notify/event_trigger.go

@@ -0,0 +1,22 @@
+// Copyright (c) 2014-2015 The Notify Authors. All rights reserved.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+// +build darwin,kqueue dragonfly freebsd netbsd openbsd solaris
+
+package notify
+
+type event struct {
+	p  string
+	e  Event
+	d  bool
+	pe interface{}
+}
+
+func (e *event) Event() Event { return e.e }
+
+func (e *event) Path() string { return e.p }
+
+func (e *event) Sys() interface{} { return e.pe }
+
+func (e *event) isDir() (bool, error) { return e.d, nil }