[mythtv] Icon Help Popup

[Stuart Morgan]

The icon help popup in playbackBox::showIconHelp needs replacing, either with 
something that can show the icon list in two columns or with a scrolling 
dialogue. There are now too many possible icons to be displayed in this 
vertically orientated dialogue.

I gave it a go but I don't have the time to get it right, so I'm just making 
everyone aware in the hope that someone might want to take a look.
-- 
Stuart Morgan