Update extension imports to flask_*

See mitsuhiko/flask#1135

{{cookiecutter.app_name}}/manage.py

@@ -3,8 +3,8 @@
 import os
 import sys
 import subprocess
-from flask.ext.script import Manager, Shell, Server
+from flask_script import Manager, Shell, Server
-from flask.ext.migrate import MigrateCommand
+from flask_migrate import MigrateCommand
 
 from {{cookiecutter.app_name}}.app import create_app
 from {{cookiecutter.app_name}}.user.models import User

{{cookiecutter.app_name}}/{{cookiecutter.app_name}}/assets.py

@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-from flask.ext.assets import Bundle, Environment
+from flask_assets import Bundle, Environment
 
 css = Bundle(
     "libs/bootstrap/dist/css/bootstrap.css",

{{cookiecutter.app_name}}/{{cookiecutter.app_name}}/extensions.py

@@ -3,20 +3,20 @@
 in app.py
 """
 
-from flask.ext.bcrypt import Bcrypt
+from flask_bcrypt import Bcrypt
 bcrypt = Bcrypt()
 
-from flask.ext.login import LoginManager
+from flask_login import LoginManager
 login_manager = LoginManager()
 
-from flask.ext.sqlalchemy import SQLAlchemy
+from flask_sqlalchemy import SQLAlchemy
 db = SQLAlchemy()
 
-from flask.ext.migrate import Migrate
+from flask_migrate import Migrate
 migrate = Migrate()
 
-from flask.ext.cache import Cache
+from flask_cache import Cache
 cache = Cache()
 
-from flask.ext.debugtoolbar import DebugToolbarExtension
+from flask_debugtoolbar import DebugToolbarExtension
 debug_toolbar = DebugToolbarExtension()

{{cookiecutter.app_name}}/{{cookiecutter.app_name}}/user/models.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 import datetime as dt
 
-from flask.ext.login import UserMixin
+from flask_login import UserMixin
 
 from {{cookiecutter.app_name}}.extensions import bcrypt
 from {{cookiecutter.app_name}}.database import (