pgsql: Remove the mostly-stubbed-out-anyway support routines for WAL

Log Message:
-----------
Remove the mostly-stubbed-out-anyway support routines for WAL UNDO.
That code is never going to be used in the foreseeable future, and
where it's more than a stub it's making the redo routines harder to
read.

Modified Files:
--------------
pgsql/src/backend/access/gist:
gist.c (r1.117 -> r1.118)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/gist/gist.c.diff?r1=1.117&r2=1.118)
pgsql/src/backend/access/hash:
hash.c (r1.79 -> r1.80)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/hash/hash.c.diff?r1=1.79&r2=1.80)
pgsql/src/backend/access/heap:
heapam.c (r1.191 -> r1.192)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/heap/heapam.c.diff?r1=1.191&r2=1.192)
pgsql/src/backend/access/nbtree:
nbtxlog.c (r1.21 -> r1.22)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/nbtree/nbtxlog.c.diff?r1=1.21&r2=1.22)
pgsql/src/backend/access/rtree:
rtree.c (r1.89 -> r1.90)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/rtree/rtree.c.diff?r1=1.89&r2=1.90)
pgsql/src/backend/access/transam:
clog.c (r1.28 -> r1.29)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/clog.c.diff?r1=1.28&r2=1.29)
rmgr.c (r1.17 -> r1.18)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/rmgr.c.diff?r1=1.17&r2=1.18)
xact.c (r1.202 -> r1.203)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xact.c.diff?r1=1.202&r2=1.203)
xlog.c (r1.195 -> r1.196)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xlog.c.diff?r1=1.195&r2=1.196)
xlogutils.c (r1.37 -> r1.38)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xlogutils.c.diff?r1=1.37&r2=1.38)
pgsql/src/backend/commands:
dbcommands.c (r1.157 -> r1.158)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/dbcommands.c.diff?r1=1.157&r2=1.158)
sequence.c (r1.120 -> r1.121)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/sequence.c.diff?r1=1.120&r2=1.121)
tablespace.c (r1.19 -> r1.20)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/tablespace.c.diff?r1=1.19&r2=1.20)
pgsql/src/backend/storage/smgr:
smgr.c (r1.87 -> r1.88)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/smgr/smgr.c.diff?r1=1.87&r2=1.88)
pgsql/src/backend/utils/init:
flatfiles.c (r1.6 -> r1.7)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/init/flatfiles.c.diff?r1=1.6&r2=1.7)
pgsql/src/include/access:
clog.h (r1.12 -> r1.13)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/clog.h.diff?r1=1.12&r2=1.13)
gist_private.h (r1.1 -> r1.2)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/gist_private.h.diff?r1=1.1&r2=1.2)
hash.h (r1.61 -> r1.62)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/hash.h.diff?r1=1.61&r2=1.62)
heapam.h (r1.100 -> r1.101)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/heapam.h.diff?r1=1.100&r2=1.101)
nbtree.h (r1.85 -> r1.86)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/nbtree.h.diff?r1=1.85&r2=1.86)
rmgr.h (r1.13 -> r1.14)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/rmgr.h.diff?r1=1.13&r2=1.14)
rtree.h (r1.38 -> r1.39)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/rtree.h.diff?r1=1.38&r2=1.39)
xact.h (r1.75 -> r1.76)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/xact.h.diff?r1=1.75&r2=1.76)
xlog.h (r1.62 -> r1.63)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/xlog.h.diff?r1=1.62&r2=1.63)
xlog_internal.h (r1.7 -> r1.8)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/xlog_internal.h.diff?r1=1.7&r2=1.8)
xlogutils.h (r1.17 -> r1.18)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/xlogutils.h.diff?r1=1.17&r2=1.18)
pgsql/src/include/commands:
dbcommands.h (r1.37 -> r1.38)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/commands/dbcommands.h.diff?r1=1.37&r2=1.38)
sequence.h (r1.30 -> r1.31)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/commands/sequence.h.diff?r1=1.30&r2=1.31)
tablespace.h (r1.8 -> r1.9)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/commands/tablespace.h.diff?r1=1.8&r2=1.9)
pgsql/src/include/storage:
smgr.h (r1.50 -> r1.51)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/smgr.h.diff?r1=1.50&r2=1.51)