Cosmetic fix for 'quick' recording options. Don't display 'this episode' if the programme is a film.
Change 'ProgramInfo::catType' from a string to an enum

This is done to prevent mistakes such as invalid values being stored
and used. Converting over exposed a bug in the handling of Dish
Network content (theme) values which would have caused Sports
programmes to be identified as a 'series' and News programmes to be
identified as 'sports'. Hopefully such bugs will become much harder to
introduce in future since enums in C++ provide greater type safety than
strings or ints.

The change ended up being much bigger than I first expected, I've been
as careful as possible to avoid regressions but I cannot test every
possible combination and code path. If you notice a bug please file a ticket,
don't assume that someone else will do so.