vocab: add ways to refer to news clips

[Meteor0id]

Thing > CreativeWork > Clip > NewsVideoFragment
Thing > CreativeWork > Clip > NewsAudioFragment

Which can be further extended by sub properties such as:

• "NewsAgency" (accepts organisation)
• "NewsReporter" (person or organisation)
• "NewsAnchor" (person)
• "NewsEvent" (text) (to describe what news event the clip is about "Storm Sandy killed 5 people in Texas")
• "NewsDate" (accept date or datetime)
• "BroadcastAgency" (organisation)
• "TVChannelName" (text)
• "RadioChannelName" (text)
• "sourceURL" (url) link to the official upload of the full video full audio broadcast.
• "columnName" (text) (I am not familliar with the proper English word for how tv or radio programs sometimes have a certain structure, deviding the programm in several parts with a different type of content. Maybe this is called a rubric? "RebricName")

I'm also pondering on

• "NewsEventType" to offer a way to distinct between for example "breaking news" at the time or a "talkshow" or "official announcement". After all, talkshows are a whole different kind of news, but can still be considered news programms. Official announcements are a planned event, but a tornado killing 5 people is a sudden unexpected news event.