[mythtv] Thoughts on new commercial detection option

[James Armstrong]

I have noticed that more and more shows are shown in letterbox (in 4:3 
format) and have black bars on the top and botton during the show but 
switch to full 4:3 during commercials. Would it be possible to add 
another commercial detection scheme that looks for the letterbox format 
with the black bars, and if present goes back to the beginning of the 
show and flags commercials when the black bars go away?

- James