Try to use tvg-id tags for channel numbering

[hazcod]

Try to use tvg-id tags for channel numbering

Fixes #63

Still needs to be tested

[tombowditch]

Need to make sure Plex allows non-int strings as a channel number because in my m3u the Tvg ID is something like "BBCOne.UK"

[hazcod]

Indeed, i've only seen non-integer ones so far in my playlists as wel.
Testing will point out.

[tombowditch]

Will test this tonight.

[hazcod]

Did you have a chance to test this? I don't have Plex or M3U streams available at the moment :(

[tombowditch]

Indeed I did - Plex does not like the non-integer strings. I propse if a strconv.Atoi (iirc) fails we just use gn

[hazcod]

I added the check @tombowditch , altough I do suggest (after merging?) that we take a deeper look at how this whole tvg-id tag system works.

Edit: it seems that Plex always expects channel numbers to be numbers and those are IDs in format tvg-id="RaiNews.it". I suggest we take XML EPG as an input and parse the channel numbers out of that.

[tombowditch]

Agreed @hazcod we need to ask for the providers XML and parse that.
For a fallback we can continue to use gn

[tombowditch]

#72 will also be handy

[hazcod]

@tombowditch what do you think about my sketchy implementation?
It's done in 10 minutes, but should give a raw idea about how we could do things.

[robbiet480]

I've rebased this on master. Can I get push access to be able to maintain this PR? I pinged both of you (well, I tried to ping you @hazcod but there were like 10 accounts) on Discord if you need to chat.

[robbiet480]

Rebase is now on my fork

[hazcod]

I will take a look at it tomorrow, thanks! Im not on Discord often.

[robbiet480]

Closing in favor of changes described in #142 and available in the new dev branch.