[mythtv] PruneList

[David Watson]

First, I want to say that I'm relly impressed with mythtv.
It's much better than anything else I've used or tried to
hack together myself.  I have some general observations I'll
post later, but I have a problem first.

I have several shows set to 'all record' that don't contain
useful show descriptions in zap2it, namely the subtitle is
empty, and the description is the same for every episode.
So, when FillRecordLists runs PruneList, all these shows
are deleted from the list.

I'd be happy to submit a patch, but I don't feel familiar enough
with the code to pick the right solution.  The record show dialog
already seems pretty overloaded, but I can't think of a good
automatic algorithm to detect this condition.

David