Add the olark feature flag to the default config and fix the usage of flask modules.

app.py

@@ -38,19 +38,10 @@ features.import_features(app.config)
 
 Principal(app, use_sessions=False)
 
-login_manager = LoginManager()
-login_manager.init_app(app)
-
-mail = Mail()
-mail.init_app(app)
-
-storage = Storage()
-storage.init_app(app)
-
-userfiles = Userfiles()
-userfiles.init_app(app)
+login_manager = LoginManager(app)
+mail = Mail(app)
+storage = Storage(app)
+userfiles = Userfiles(app)
+analytics = Analytics(app)
 
 stripe.api_key = app.config.get('STRIPE_SECRET_KEY', None)
-
-analytics = Analytics()
-analytics.init_app(app)

config.py

@@ -134,3 +134,6 @@ class DefaultConfig(object):
 
   # Feature Flag: Whether GitHub login is supported.
   FEATURE_GITHUB_LOGIN = True
+
+  # Feature flag, whether to enable olark chat
+  FEATURE_OLARK_CHAT = True