[PATCH] xutil.c: remove duplicate copies, create new library libutil.a to contain xutil.

[Austin Clements]

LGTM.  Code deduplication is always a good thing.

"Internal interfaces for notmuch." doesn't seem like the best summary
for util/error_util.h

On Sun, Oct 23, 2011 at 11:18 AM, David Bremner <david at tethera.net> wrote:
> From: David Bremner <bremner at debian.org>
>
> We keep the lib/xutil.c version. As a consequence, also factor out
> _internal_error and associated macros.  It might be overkill to make a
> new file error_util.c for this, but _internal_error does not really
> belong in database.cc.