pgsql: Create a GUC parameter temp_tablespaces that allows selection of

Log Message:
-----------
Create a GUC parameter temp_tablespaces that allows selection of the
tablespace(s) in which to store temp tables and temporary files.  This is a
list to allow spreading the load across multiple tablespaces (a random list
element is chosen each time a temp object is to be created).  Temp files are
not stored in per-database pgsql_tmp/ directories anymore, but per-tablespace
directories.

Jaime Casanova and Albert Cervera, with review by Bernd Helmle and Tom Lane.

Modified Files:
--------------
    pgsql/doc/src/sgml:
        config.sgml (r1.124 -> r1.125)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/config.sgml.diff?r1=1.124&r2=1.125)
        manage-ag.sgml (r2.53 -> r2.54)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/manage-ag.sgml.diff?r1=2.53&r2=2.54)
        storage.sgml (r1.17 -> r1.18)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/storage.sgml.diff?r1=1.17&r2=1.18)
    pgsql/doc/src/sgml/ref:
        create_index.sgml (r1.62 -> r1.63)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/create_index.sgml.diff?r1=1.62&r2=1.63)
        create_table.sgml (r1.107 -> r1.108)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/create_table.sgml.diff?r1=1.107&r2=1.108)
        create_table_as.sgml (r1.36 -> r1.37)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/create_table_as.sgml.diff?r1=1.36&r2=1.37)
        drop_tablespace.sgml (r1.6 -> r1.7)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/drop_tablespace.sgml.diff?r1=1.6&r2=1.7)
        grant.sgml (r1.65 -> r1.66)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/grant.sgml.diff?r1=1.65&r2=1.66)
    pgsql/src/backend/commands:
        indexcmds.c (r1.158 -> r1.159)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/indexcmds.c.diff?r1=1.158&r2=1.159)
        tablecmds.c (r1.225 -> r1.226)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/tablecmds.c.diff?r1=1.225&r2=1.226)
        tablespace.c (r1.46 -> r1.47)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/tablespace.c.diff?r1=1.46&r2=1.47)
    pgsql/src/backend/executor:
        execMain.c (r1.293 -> r1.294)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/execMain.c.diff?r1=1.293&r2=1.294)
        nodeHash.c (r1.112 -> r1.113)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/nodeHash.c.diff?r1=1.112&r2=1.113)
        nodeHashjoin.c (r1.89 -> r1.90)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/nodeHashjoin.c.diff?r1=1.89&r2=1.90)
    pgsql/src/backend/storage/file:
        buffile.c (r1.26 -> r1.27)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/file/buffile.c.diff?r1=1.26&r2=1.27)
        fd.c (r1.137 -> r1.138)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/file/fd.c.diff?r1=1.137&r2=1.138)
    pgsql/src/backend/utils/misc:
        guc.c (r1.392 -> r1.393)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/guc.c.diff?r1=1.392&r2=1.393)
        postgresql.conf.sample (r1.215 -> r1.216)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/postgresql.conf.sample.diff?r1=1.215&r2=1.216)
    pgsql/src/backend/utils/sort:
        logtape.c (r1.23 -> r1.24)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/sort/logtape.c.diff?r1=1.23&r2=1.24)
        tuplestore.c (r1.31 -> r1.32)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/sort/tuplestore.c.diff?r1=1.31&r2=1.32)
    pgsql/src/include/commands:
        tablespace.h (r1.16 -> r1.17)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/commands/tablespace.h.diff?r1=1.16&r2=1.17)
    pgsql/src/include/executor:
        hashjoin.h (r1.45 -> r1.46)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/executor/hashjoin.h.diff?r1=1.45&r2=1.46)
        nodeHashjoin.h (r1.34 -> r1.35)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/executor/nodeHashjoin.h.diff?r1=1.34&r2=1.35)
    pgsql/src/include/storage:
        buffile.h (r1.20 -> r1.21)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/buffile.h.diff?r1=1.20&r2=1.21)
        fd.h (r1.57 -> r1.58)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/fd.h.diff?r1=1.57&r2=1.58)
    pgsql/src/include/utils:
        guc.h (r1.81 -> r1.82)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/guc.h.diff?r1=1.81&r2=1.82)