[0/5] dtc: srcpos, input handling cleanups

[David Gibson]

While working on the expression / macro / function support stuff, my
irritation with some uglies I've been meaning to clean up for ages
reached critical point.

So, here's a patch series cleaning up the input file handling, and the
srcpos / parser location tracking stuff.  This is a fusion of some
stuff I've had on the back-burner for a while with the srcpos related
pieces from jdl's interpreted language series.

I'm pretty happy with patches 1-4, but 5 probably needs a bit more
polish, and I'd like to add another patch adding column number
tracking and a cleaner way of doing line tracking.  But it's late and
I'd like to get what I have out for people to look at.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson