deps: Upgrade and move winchan.js from static/third to npm

- Remove `winchan.js` from `static/third` and fetch it from `npm`.
- Upgrade `winchan` to 0.2.0.
- Bump up the `PROVISION_VERSION` to 4.0.

Fixes zulip#1709.

first 4.00

docs/THIRDPARTY

@@ -196,11 +196,6 @@ Copyright: 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters
 License: Expat
 Comment: https://github.com/jashkenas/underscore/blob/master/LICENSE
 
-Files: static/third/winchan/*
-Copyright: 2012 Lloyd Hilaiel
-License: Expat
-Comment: https://github.com/mozilla/winchan
-
 Files: static/third/xdate/*
 Copyright: 2010 C. F., Wong
 License: Expat

package.json

@@ -15,6 +15,7 @@
     "jquery-validation": "1.15.1",
     "plotly.js": "1.19.2",
     "webpack": "1.12.2",
+    "winchan": "0.2.0",
     "zxcvbn": "4.4.1"
   },
   "devDependencies": {

version.py

@@ -1,2 +1,2 @@
 ZULIP_VERSION = "1.4.1+git"
-PROVISION_VERSION = '3.2'
+PROVISION_VERSION = '4.0'

zproject/settings.py

@@ -768,8 +768,8 @@ def get_secret(key):
             'third/lazyload/lazyload.js',
             'third/spectrum/spectrum.js',
             'third/string-prototype-codepointat/codepointat.js',
-            'third/winchan/winchan.js',
             'third/sockjs/sockjs-0.3.4.js',
+            'node_modules/winchan/winchan.js',
             'third/handlebars/handlebars.runtime.js',
             'third/marked/lib/marked.js',
             'templates/compiled.js',