[mythtv] OK, figured out the problem when running setup

[Dan Schwarz]

Here's the problem:  probeCard(...) failed to open /dev/video  (probably 
I've got the wrong permissions set on /dev/video) so it can't determine 
the card inputs.

It emits a warning message  "Couldn't open /dev/video to probe its 
inputs."  but does not stop the process. Everything continues as if 
nothing went wrong (although of course you don't get your inputs 
associated with the channel sources)

New users who are not paying close attention will not see the message. 
They will certainly not understand that they have to fix permissions on 
/dev/video, or do some other operation, in order for mythTV to operate 
correctly.

I think the above error should stop the setup process and display a 
prompt message with the default to halt setup so the user can correct 
the error and re-run.  

I'll submit a patch to that effect if Isaac agrees.  

Regards,

Dan