Committed the NEW/DISPOSE/etc. conversion

[Russ Allbery]

I've commited the conversion of all uses of NEW/DISPOSE/COPY/RENEW to
xmalloc and friends.  This conversion was entirely mechanical except for
NEW and RENEW, where if the type was something other than char, the code
had to be rewritten like the macro does.  Accordingly, it's possible that
I made a mistake somewhere, although I did look over all of the chances
twice.

I'm continuing on to some of the other mechanical changes.

Looking over the code, there are a *lot* of opportunities for cleanup,
particularly in the areas of using inn/buffer.h for most places that we
want persistant memory allocation sitting around.  There also appear to be
a lot of places where we should be calling xcalloc instead of doing the
memset ourselves and similar sorts of things.  I may look at some of that,
but I don't know how much time I'll have.  Those are things that can be
done slowly over time, anyway.

-- 
Russ Allbery (rra at stanford.edu)             <http://www.eyrie.org/~eagle/>