An initial version of the BroadcastEventGenerator, with a bunch of hardcoding, and some (very basic) testing.
Of note:
 - constants are BBC specific. These need pulling out to the PublisherConfigFactory.
 - testing is not super thorough.
 - some of the tests now rely on LoveFilm data not having broadcasts, thanks to javax constructors throwing exceptions
 - A start has been made on moving boilerplate around construction of TVA elements to a helper class, but this needs backporting to the existing generators.