Support HTTP basic auth via configuration

[Bustel]

Right now if I want to subscribe a room to a private feed I can do so via https://user:pass@feed.example.org/rss. This is however, unsatisfying because it exposes my credentials to the whole room.

A better solution would be to utilize aiohttp's basic auth capabilities for certain domains if an RSS admin does the subscription.

Some necessary steps:

• Check headers['www-authenticate'] in parse_feed for 'Basic realm="Use test/basic"' This indicates that auth is needed
• Add new configuration item, sth. like:

  private_feeds:
    - url: "*.example.org"
      user: johndoe
      pw: supersecure

• If we have credentials for the url, then self.http.get(url, auth=aiohttp.BasicAuth(user, pass))
• If a subscription matches a private feed, only an rss-admin should be allowed to manage it

What do you think about such an enhancement? I would consider providing a pull request but i dont have a good dev setup here to test it.

[xrayn]

I would love to have such a feature too!