deprecate both this.Funnel and this.pickFiles

this wasn’t really intended for public API, users should depend on their own packages.

lib/models/addon.js

@@ -23,6 +23,10 @@ var AddonsFactory   = require('../models/addons-factory');
 var CoreObject = require('core-object');
 var Project = require('./project');
 
+var mergeTrees = require('broccoli-merge-trees');
+var Funnel     = require('broccoli-funnel');
+var walkSync   = require('walk-sync');
+
 /**
   Root class for an Addon. If your addon module exports an Object this
   will be extended from this base class. If you export a constructor (function),
@@ -112,14 +116,17 @@ Addon.prototype._requireBuildPackages = function() {
 
   this.transpileModules  = this.transpileModules || require('broccoli-es6modules');
 
-  this.mergeTrees  = this.mergeTrees || require('broccoli-merge-trees');
-  this.Funnel      = this.Funnel     || require('broccoli-funnel');
-  this.walkSync    = this.walkSync   || require('walk-sync');
+  var ui = this.ui;
+
+  this.Funnel = function FunnelFactory(tree, options) {
+    ui.writeLine('[Deprecated] new this.Funnel(..) is deprecated, please use broccoli-funnel directly instead  [addon: ' + this.name + ']');
+    return new Funnel(tree, options)
+  };
 
   this.pickFiles = function(tree, options) {
-    this.ui.writeLine('[Deprecated] this.pickFiles(..) is deprecated in-favour of new this.Funnel(..)  [addon: ' + this.name + ']');
-    return new this.Funnel(tree, options);
-  }.bind(this);
+    ui.writeLine('[Deprecated] this.pickFiles(..) is deprecated, please use broccoli-funnel directly instead  [addon: ' + this.name + ']');
+    return new Funnel(tree, options);
+  };
 };
 
 /**