[PATCH] Contrib C source for casting MONEY to INT[248] and FLOAT[48]

Attached please find a patch to cast (convert) the MONEY type to any one
of the following types:

  INT2, INT4, INT8, FLOAT4, FLOAT8

The patch is against PostgreSQL v7.0.3 and creates files in a new
directory named contrib/money/.  I'm pretty sure it won't compile
against v7.1, but it won't be too hard to fix.  (I'll do this when I
upgrade to v7.1 at work, which will hopefully happen sooner rather than
later.)

I wrote this because I needed to convert MONEY to a standard decimal
value and didn't want to do it on the client in Perl, and I didn't want
to use a plpgsql function that used string parsing.  Both solutions were
too inefficient for my needs.

  http://postgresql.bteg.net/mhonarc/pgsql-general/2000-01/msg00446.html

I wouldn't have used the MONEY type in the first place if I had known it
was deprecated, but I didn't see this notice in the v7.0.3 documentation
two to three months ago when designing the database.  Oh well, my loss
is your gain.  :^)

I've attempted to set the Reply-To field to pgsql-hackers, but please
copy me on any posts as well.

Comments welcome!

Dave