pgsql: Redefine Datum as uintptr_t, instead of unsigned long.

Log Message:
-----------
Redefine Datum as uintptr_t, instead of unsigned long.

This is more in keeping with modern practice, and is a first step towards
porting to Win64 (which has sizeof(pointer) > sizeof(long)).

Tsutomu Yamada, Magnus Hagander, Tom Lane

Modified Files:
--------------
    pgsql:
        configure (r1.663 -> r1.664)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/configure?r1=1.663&r2=1.664)
        configure.in (r1.616 -> r1.617)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/configure.in?r1=1.616&r2=1.617)
    pgsql/src/backend/access/common:
        heaptuple.c (r1.127 -> r1.128)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/common/heaptuple.c?r1=1.127&r2=1.128)
    pgsql/src/backend/access/hash:
        hashfunc.c (r1.59 -> r1.60)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/hash/hashfunc.c?r1=1.59&r2=1.60)
    pgsql/src/backend/port/hpux:
        tas.c.template (r1.2 -> r1.3)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/port/hpux/tas.c.template?r1=1.2&r2=1.3)
    pgsql/src/backend/storage/lmgr:
        lwlock.c (r1.53 -> r1.54)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/lmgr/lwlock.c?r1=1.53&r2=1.54)
    pgsql/src/backend/utils/misc:
        guc.c (r1.529 -> r1.530)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/guc.c?r1=1.529&r2=1.530)
    pgsql/src/include/access:
        tupmacs.h (r1.36 -> r1.37)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/access/tupmacs.h?r1=1.36&r2=1.37)
    pgsql/src/include:
        c.h (r1.236 -> r1.237)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/c.h?r1=1.236&r2=1.237)
        pg_config.h.in (r1.143 -> r1.144)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/pg_config.h.in?r1=1.143&r2=1.144)
        pg_config.h.win32 (r1.64 -> r1.65)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/pg_config.h.win32?r1=1.64&r2=1.65)
        postgres.h (r1.92 -> r1.93)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/postgres.h?r1=1.92&r2=1.93)
    pgsql/src/include/storage:
        s_lock.h (r1.167 -> r1.168)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/s_lock.h?r1=1.167&r2=1.168)
    pgsql/src/interfaces/ecpg/ecpglib:
        data.c (r1.46 -> r1.47)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/ecpglib/data.c?r1=1.46&r2=1.47)
    pgsql/src/pl/plperl:
        plperl.c (r1.156 -> r1.157)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plperl/plperl.c?r1=1.156&r2=1.157)
    pgsql/src/pl/tcl:
        pltcl.c (r1.128 -> r1.129)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/tcl/pltcl.c?r1=1.128&r2=1.129)