pgsql: Add temp_buffers GUC variable to allow users to determine the

Log Message:
-----------
Add temp_buffers GUC variable to allow users to determine the size
of the local buffer arena for temporary table access.

Modified Files:
--------------
pgsql/doc/src/sgml:
runtime.sgml (r1.309 -> r1.310)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/runtime.sgml.diff?r1=1.309&r2=1.310)
pgsql/src/backend/storage/buffer:
localbuf.c (r1.65 -> r1.66)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/buffer/localbuf.c.diff?r1=1.65&r2=1.66)
pgsql/src/backend/utils/init:
postinit.c (r1.143 -> r1.144)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/init/postinit.c.diff?r1=1.143&r2=1.144)
pgsql/src/backend/utils/misc:
guc.c (r1.255 -> r1.256)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/guc.c.diff?r1=1.255&r2=1.256)
postgresql.conf.sample (r1.136 -> r1.137)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/postgresql.conf.sample.diff?r1=1.136&r2=1.137)
pgsql/src/bin/psql:
tab-complete.c (r1.121 -> r1.122)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/tab-complete.c.diff?r1=1.121&r2=1.122)
pgsql/src/include/storage:
bufmgr.h (r1.91 -> r1.92)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/bufmgr.h.diff?r1=1.91&r2=1.92)
pgsql/src/include/utils:
guc.h (r1.58 -> r1.59)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/guc.h.diff?r1=1.58&r2=1.59)