[Enhance] Some config options & Login limiter

- Add limiter for login and API login
- Add some config options

- Delete `setting.py` files

latest version/main.py

@@ -12,6 +12,7 @@ from flask import Flask, make_response, request, send_from_directory
 from core.config_manager import Config, ConfigManager
 
 if os.path.exists('config.py') or os.path.exists('config'):
+    # 导入用户自定义配置
     ConfigManager.load(import_module('config').Config)
 
 
@@ -29,10 +30,14 @@ from server.func import error_return
 
 app = Flask(__name__)
 
-# from werkzeug.middleware.proxy_fix import ProxyFix
-# app.wsgi_app = ProxyFix(app.wsgi_app, x_proto=1, x_host=1)
-# from flask_cors import CORS
-# CORS(app, supports_credentials=True)
+if Config.USE_PROXY_FIX:
+    # 代理修复
+    from werkzeug.middleware.proxy_fix import ProxyFix
+    app.wsgi_app = ProxyFix(app.wsgi_app, x_proto=1, x_host=1)
+if Config.USE_CORS:
+    # 服务端跨域
+    from flask_cors import CORS
+    CORS(app, supports_credentials=True)
 
 
 os.chdir(sys.path[0])  # 更改工作路径，以便于愉快使用相对路径
@@ -73,10 +78,12 @@ def download(file_path):
             if not x.is_valid:
                 raise NoAccess('Expired token.')
             x.download_hit()
-            # response = make_response()
-            # response.headers['Content-Type'] = 'application/octet-stream'
-            # response.headers['X-Accel-Redirect'] = '/nginx_download/' + file_path
-            # return response
+            if Config.DOWNLOAD_USE_NGINX_X_ACCEL_REDIRECT:
+                # nginx X-Accel-Redirect
+                response = make_response()
+                response.headers['Content-Type'] = 'application/octet-stream'
+                response.headers['X-Accel-Redirect'] = Config.NGINX_X_ACCEL_REDIRECT_PREFIX + file_path
+                return response
             return send_from_directory(Constant.SONG_FILE_FOLDER_PATH, file_path, as_attachment=True, conditional=True)
         except ArcError as e:
             if Config.ALLOW_WARNING_LOG:
@@ -86,9 +93,12 @@ def download(file_path):
 
 
 def tcp_server_run():
-    if False:
+    if Config.USE_GEVENT_WSGI:
+        # 异步 gevent WSGI server
+        host_port = (Config.HOST, Config.PORT)
+        app.logger.info('Running gevent WSGI server... (%s:%s)' % host_port)
         from gevent.pywsgi import WSGIServer
-        WSGIServer(("127.0.0.1", 5000), app).serve_forever()
+        WSGIServer(host_port, app).serve_forever()
     else:
         if Config.SSL_CERT and Config.SSL_KEY:
             app.run(Config.HOST, Config.PORT, ssl_context=(