PSA: Countermeasures to abuse

[Rob--W]

In response to multiple DMCA requests via Heroku, and to counter the risk of a full shut down of the service, I am taking the following measures to limit abuse:

• The number of requests per hour is lowered. It used to be 600 (from Restrict access of public CORS Anywhere demo #45); it is now 200. This is not just to counter abusive content, but also to prevent a small number of users from using all resources (503 http error on live server #155).
• All m3u8 files are blocked (it is abused too often - Consider blocking radio streams #129).

If more signs of abuse occur, I will have to lower the limit even more, and/or block even more kinds of content. So please be a good citizen and only use the public demo for small tests and experiments. If you need more quota, self-host the application. The config of the demo server is explained in the README, and there are various other Q&A's in this issue tracker about self-hosting.