Exclude certain live streams

[IronCraftMan]

Some channels have 24/7 live streams, which I'm not interested in recording. They do, however, sometimes have a second stream which I am interested in recording. I see in #98 you don't want to support multiple live streams, but I am using the channel monitoring feature, with a /live url, so it's not possible to have multiple instances running (they will all download the 24/7 stream).

So I'm wondering if it's possible to give ytarchive a video ID to ignore, and have it keep waiting for any other streams that might go live. Obviously this isn't perfect if the 24/7 stream ID changes, but it's better than having to manually check for live streams.

[Kethsar]

This would probably fall under #81.