Also run it across the whole tree to get everything using the One True Style.
We don't yet run this in an automated fashion as it's a little slow, but
there is a snippet to do so in makeall.sh.
Also introduce more seek modes on CIODevice, and an out param to find
the current position inside the file -- this means less syscalls (and
less potential races) than requesting it through a separate pos()
accessor or something.
