[mythtv] Right way to use gContext

[thor]

Isaac (et al),

	Just rolled a couple tiny changes in libmyth into CVS. I changed mythcontext 
so that it holds an lcd device object. Also updated mythlcd to use the 
gContext to access an lcd.

	gContext looks like the right place to be doing this sort of thing, as no 
matter how many screens may appear on a given frontend, there is only one LCD 
display (at least in a typical end user scenario).

	Before I start updating mythfronted/backend to make LCD calls, just wanted to 
give you a chance to slap me down if MythContext is *not* the right place to 
be trying to do this. 

BR,

- thor