pgsql: Attached patch is required ot build with the CRT that comes with

Log Message:
-----------
Attached patch is required ot build with the CRT that comes with Visual
Studio 2005. Basically MS defined errcode in the headers with a typedef,
so we have to #define it out of the way.

While at it, fix a function declaration in plpython that didn't match
the implementation (volatile missing).

Magnus Hagander

Modified Files:
--------------
    pgsql/src/include:
        c.h (r1.205 -> r1.206)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/c.h.diff?r1=1.205&r2=1.206)
    pgsql/src/pl/plpython:
        plpython.c (r1.83 -> r1.84)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/plpython.c.diff?r1=1.83&r2=1.84)