pgsql: Rename the members of CommandDest enum so they don't collide with

Log Message:
-----------
Rename the members of CommandDest enum so they don't collide with other uses of
those names.  (Debug and None were pretty bad names anyway.)  I hope I catched
all uses of the names in comments too.

Modified Files:
--------------
    pgsql/src/backend/access/common:
        printtup.c (r1.92 -> r1.93)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/common/printtup.c.diff?r1=1.92&r2=1.93)
    pgsql/src/backend/commands:
        async.c (r1.126 -> r1.127)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/async.c.diff?r1=1.126&r2=1.127)
        copy.c (r1.253 -> r1.254)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/copy.c.diff?r1=1.253&r2=1.254)
        portalcmds.c (r1.43 -> r1.44)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/portalcmds.c.diff?r1=1.43&r2=1.44)
    pgsql/src/backend/executor:
        spi.c (r1.143 -> r1.144)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/spi.c.diff?r1=1.143&r2=1.144)
        tstoreReceiver.c (r1.14 -> r1.15)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/tstoreReceiver.c.diff?r1=1.14&r2=1.15)
    pgsql/src/backend/postmaster:
        postmaster.c (r1.472 -> r1.473)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/postmaster/postmaster.c.diff?r1=1.472&r2=1.473)
    pgsql/src/backend/tcop:
        dest.c (r1.66 -> r1.67)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/tcop/dest.c.diff?r1=1.66&r2=1.67)
        postgres.c (r1.467 -> r1.468)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/tcop/postgres.c.diff?r1=1.467&r2=1.468)
        pquery.c (r1.95 -> r1.96)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/tcop/pquery.c.diff?r1=1.95&r2=1.96)
    pgsql/src/backend/utils/error:
        elog.c (r1.165 -> r1.166)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/error/elog.c.diff?r1=1.165&r2=1.166)
    pgsql/src/backend/utils/misc:
        guc.c (r1.296 -> r1.297)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/guc.c.diff?r1=1.296&r2=1.297)
    pgsql/src/include/tcop:
        dest.h (r1.47 -> r1.48)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/tcop/dest.h.diff?r1=1.47&r2=1.48)