[fix refactor] Use watch.watchTree function

We want to listen on all events, so it's better to use `watch.watchTree`
than `watch.createMonitor`.

lib/forever/monitor.js

@@ -394,17 +394,20 @@ Monitor.prototype.watch = function () {
       Array.prototype.push.apply(self.watchIgnorePatterns, data.split('\n'));
   });
 
-  watch.createMonitor(
-    this.watchDirectory,
-    function (monitor) {
-      monitor.on('changed', function (f, curr, prev) {
-        if (self._watchFilter(f)) {
-          self.info('restaring script because ' + f + ' changed');
-          self.restart();
-        }
-      });
-    }
-  );
+  watch.watchTree(this.watchDirectory, function (f, curr, prev) {
+    if (!(curr == null && prev == null && typeof f == 'object')) {
+      //
+      // `curr` == null && `prev` == null && typeof f == "object" when watch
+      // finishes walking the tree to add listeners. We don't need to know
+      // about it, so we simply ignore it (anything different means that
+      // some file changed/was removed/created - that's what we want to know).
+      //
+      if (self._watchFilter(f)) {
+        self.info('restaring script because ' + f + ' changed');
+        self.restart();
+      }
+    };
+  });
 };
 
 //