[mythtv] Backend deadlock ticket #13479 analysis - any comments

[Peter Bennett]

I am tired of my backend freezing when I edit metadata on the frontend.

See ticket https://code.mythtv.org/trac/ticket/13479

I believe that I have found the cause, based on the backtrace. If 
anybody feels inclined, please let me know if there is anything wrong 
with my analysis, and let me know if you have any better solution than 
what I have proposed in the ticket.

Thanks
Peter