pgsql: Fix handling of restricted processes for Windows Vista (mainly),

Log Message:
-----------
Fix handling of restricted processes for Windows Vista (mainly),
by explicitly adding back the user to the DACL of the new process.
This fixes the failure case when executing as the Administrator
user, which had no permissions left at all after we dropped the
Administrators group.

Dave Page with some modifications from me

Modified Files:
--------------
    pgsql/src/bin/initdb:
        initdb.c (r1.153 -> r1.154)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/initdb/initdb.c?r1=1.153&r2=1.154)
    pgsql/src/bin/pg_ctl:
        pg_ctl.c (r1.94 -> r1.95)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_ctl/pg_ctl.c?r1=1.94&r2=1.95)
    pgsql/src/include:
        port.h (r1.117 -> r1.118)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/port.h?r1=1.117&r2=1.118)
    pgsql/src/port:
        exec.c (r1.57 -> r1.58)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/port/exec.c?r1=1.57&r2=1.58)