[0/5] Input file and srcpos rework (v2)

[David Gibson]

Here's a rebased and revised version of my series of source file
handling and srcpos tracking cleanups.  I've also included my patch to
move existing utility functions into util.c; sorry for the repeat
send, but it seemed clearer since I think one of the later patches
will conflict without it.

-- 
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