pgsql: Remove some dead code for handling XLOG_DBASE_CREATE_OLD and

Log Message:
-----------
Remove some dead code for handling XLOG_DBASE_CREATE_OLD and
XLOG_DBASE_DROP_OLD WAL records -- these records are no longer created in
current sources. Adjust numbering of XLOG_DBASE_CREATE and XLOG_DBASE_DROP
and bump the catversion. Patch from Gavin Sherry, adjusted by Neil Conway.

Modified Files:
--------------
    pgsql/src/backend/commands:
        dbcommands.c (r1.165 -> r1.166)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/dbcommands.c.diff?r1=1.165&r2=1.166)
    pgsql/src/include/catalog:
        catversion.h (r1.285 -> r1.286)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h.diff?r1=1.285&r2=1.286)
    pgsql/src/include/commands:
        dbcommands.h (r1.39 -> r1.40)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/commands/dbcommands.h.diff?r1=1.39&r2=1.40)