pgsql: Check the file system on postmaster startup and report any

Log Message:
-----------
Check the file system on postmaster startup and report any unreferenced
files in the server log.

Heikki Linnakangas

Modified Files:
--------------
pgsql/doc/src/sgml:
maintenance.sgml (r1.41 -> r1.42)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/maintenance.sgml.diff?r1=1.41&r2=1.42)
pgsql/src/backend/access/transam:
xlog.c (r1.189 -> r1.190)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xlog.c.diff?r1=1.189&r2=1.190)
pgsql/src/backend/catalog:
catalog.c (r1.59 -> r1.60)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/catalog.c.diff?r1=1.59&r2=1.60)
pgsql/src/backend/commands:
tablespace.c (r1.17 -> r1.18)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/tablespace.c.diff?r1=1.17&r2=1.18)
pgsql/src/backend/utils/adt:
misc.c (r1.40 -> r1.41)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/misc.c.diff?r1=1.40&r2=1.41)
pgsql/src/backend/utils/init:
Makefile (r1.18 -> r1.19)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/init/Makefile.diff?r1=1.18&r2=1.19)
pgsql/src/include/catalog:
catalog.h (r1.30 -> r1.31)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catalog.h.diff?r1=1.30&r2=1.31)
pgsql/src/include/utils:
flatfiles.h (r1.1 -> r1.2)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/flatfiles.h.diff?r1=1.1&r2=1.2)

Added Files:
-----------
pgsql/src/backend/utils/init:
checkfiles.c (r1.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/init/checkfiles.c?rev=1.1&content-type=text/x-cvsweb-markup)