Revert "pkg: remove unused filenotify"

This reverts commit ee99b5f2e96aafa982487aadbb78478898ae0c71.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>

filenotify/filenotify.go

@@ -0,0 +1,40 @@
+// Package filenotify provides a mechanism for watching file(s) for changes.
+// Generally leans on fsnotify, but provides a poll-based notifier which fsnotify does not support.
+// These are wrapped up in a common interface so that either can be used interchangeably in your code.
+package filenotify
+
+import "gopkg.in/fsnotify.v1"
+
+// FileWatcher is an interface for implementing file notification watchers
+type FileWatcher interface {
+	Events() <-chan fsnotify.Event
+	Errors() <-chan error
+	Add(name string) error
+	Remove(name string) error
+	Close() error
+}
+
+// New tries to use an fs-event watcher, and falls back to the poller if there is an error
+func New() (FileWatcher, error) {
+	if watcher, err := NewEventWatcher(); err == nil {
+		return watcher, nil
+	}
+	return NewPollingWatcher(), nil
+}
+
+// NewPollingWatcher returns a poll-based file watcher
+func NewPollingWatcher() FileWatcher {
+	return &filePoller{
+		events: make(chan fsnotify.Event),
+		errors: make(chan error),
+	}
+}
+
+// NewEventWatcher returns an fs-event based file watcher
+func NewEventWatcher() (FileWatcher, error) {
+	watcher, err := fsnotify.NewWatcher()
+	if err != nil {
+		return nil, err
+	}
+	return &fsNotifyWatcher{watcher}, nil
+}