Waiting for updating and fix some bugs

It will be released soon because lowiro will update in some days.
Fix many bugs and I forgot them. :<

I push this because there's a small but serious safety problem. It should be fixed immediately.

Oh, and this update needs you to login in arcaea again because a new function is added.

latest version/setting.py

@@ -0,0 +1,62 @@
+class Config():
+    '''
+    This is the setting file. You can change some parameters here.
+    '''
+
+    '''
+    --------------------
+    主机的地址和端口号
+    Host and port of your server
+    '''
+    HOST = '192.168.1.113'
+    PORT = '80'
+    '''
+    --------------------
+    '''
+
+    '''
+    --------------------
+    Web后台管理页面的用户名和密码
+    Username and password of web background management page
+    '''
+    USERNAME = 'admin'
+    PASSWORD = 'admin'
+    '''
+    --------------------
+    '''
+
+    '''
+    --------------------
+    Web后台管理页面的session秘钥，如果不知道是什么，请不要修改
+    Session key of web background management page
+    If you don't know what it is, please don't modify it.
+    '''
+    SECRET_KEY = '1145141919810'
+    '''
+    --------------------
+    '''
+
+    '''
+    --------------------
+    玩家歌曲下载的24小时次数限制
+    Player's song download limit times in 24 hours
+    '''
+    DOWNLOAD_TIMES_LIMIT = 3000
+    '''
+    歌曲下载链接的有效时长，单位：秒
+    Effective duration of song download link, unit: seconds
+    '''
+    DOWNLOAD_TIME_GAP_LIMIT = 1000
+    '''
+    --------------------
+    '''
+
+    '''
+    --------------------
+    Arcaea登录的最大允许设备数量，最小值为1
+    The maximum number of devices allowed to log in Arcaea, minimum: 1
+    '''
+    LOGIN_DEVICE_NUMBER_LIMIT = 1
+    '''
+    --------------------
+    '''