Improved Extinf support

[iain17]

Thanks for work you've done. Sadly it didn't support my use case. So I made the following changes.

Extinf wouldn't read the title properly, it now does. Also it didn't read the properties sent along, it does now. See:

#EXTINF:-1 tvg-ID="" tvg-name="example" custom-attribute="" group-title="another example",title: of channel
http://media.example.com/fourth.ts

Also added a unit test for this use case.