[Developers] Updating /tv/tv_series_episode/production_number expected type to /type/rawstring

[Bryan Cheung]

https://bugs.freebase.com/browse/DA-886

The property /tv/tv_series_episode/production_number has an expected  
type of /type/text , which really should be /type/rawstring.  I'd like  
to update the expected type.  Unless there are queries relying on a  
lang returning from a mql read, this shouldn't be too disruptive.   
Will this update affect anyone's application?

Bryan