[mythtv] Default duplicate check method

[James Fidell]

On a related note:

I use primarily RT data for my schedules, but EIT data for Freeview
channels where RT data isn't available.  I've noticed that particulary
for Radio 7 (and possibly for Radio 4, too) the programme descriptions
for repeats match with the exception of a "[Rptd at ... ]." section at
the end.

I was going to try to ignore that part in the code that matches
programmes for duplicates, but the SQL was becoming hideous, so I've
changed the EIT fixup code to (I hope :) drop that text.  I'm testing it
at the moment.

James