Fixed issues with parsing, added parsing of IFrames

[dipoll]

• Added IFrame streams as a separate slice attribute.
• ProgramID parsing, because nowadays, HLS version 3 is very common
• Map parsing with @ sign

[ollytom]

Thank you! Very busy at work but just want to say thanks for sending this over :)

[dipoll]

Same there :) Found another bug btw. Looks like many vendors are adding custom attributes to various tags. So I think it is good to skip everything, or add them to the map ...