switch to flask_login, finish login implementation, add basic home page

app/__init__.py

@@ -1,9 +1,15 @@
 from flask import Flask
 from flask_socketio import SocketIO
+from flask_login import LoginManager
 from .db import close_db, init_db
-
+from app.models.user import User
 
 sIO = SocketIO()
+login_manager = LoginManager()
+
+@login_manager.user_loader
+def load_user(user_id):
+    return User.get(user_id)
 
 def create_app():
     app = Flask(__name__)
@@ -12,6 +18,7 @@ def create_app():
     app.teardown_appcontext(close_db)
     
     sIO.init_app(app)
+    login_manager.init_app(app)
 
     from .routes.auth import auth_bp
     from .routes.main import main_bp