[mythtv] OSD Image Caching

[Stuart Morgan]

I'm not sure that I've got a grip on what is supposed to be happening with the 
OSD image caching, so maybe someone could point me in the right direction.

Channel icons are cached, yet OSD::SetInfoText and OSD::SetText don't use the 
cache when loading them, which appears to defeat the point? Is there are good 
reason for this, was it an oversight or am I missing something?

Which images should not be cached and should the default be changed to cache 
all images except those?
-- 
Stuart Morgan