Allow passing credits with the EPG data

[michaelarnauts]

Allow to pass credits to the EPG data

An optional list of credits can be supplied for a program. A credit is an object with the property type that can be actor, director, writer, adapter, producer, composer, editor, presenter, commentator or guest, and a property name that contains the name of the person. For the type actor, an optional property role can be added to give the name of the character that is played.

Examples:

• {"type": "director", "name": "David Benioff"}
• {"type": "writer", "name": "George R.R. Martin"}
• {"type": "actor", "name": "Kit Harington", "role": "John Snow"}

Notes

• The types are based on the values that xmltv supports and seem like a good list of possible items. It also closely matched the different types I saw in the API of TV Vlaanderen.
• IPTV Simple only supports director, writer and actor, so we have to make a mapping when writing the EPG.
• Also, when a parsing error occurs, we log it and continue with the next program instead of just stopping the processing.