Spellchecking run, final cleanups

doc/src/sgml/array.sgml

doc/src/sgml/backup.sgml

doc/src/sgml/catalogs.sgml

doc/src/sgml/charset.sgml

doc/src/sgml/client-auth.sgml

doc/src/sgml/config.sgml

doc/src/sgml/cvs.sgml

doc/src/sgml/ddl.sgml

doc/src/sgml/ecpg.sgml

doc/src/sgml/func.sgml

doc/src/sgml/gist.sgml

doc/src/sgml/indexam.sgml

doc/src/sgml/indices.sgml

doc/src/sgml/libpq.sgml

doc/src/sgml/maintenance.sgml

doc/src/sgml/nls.sgml

doc/src/sgml/perform.sgml

doc/src/sgml/planstats.sgml

doc/src/sgml/plperl.sgml

doc/src/sgml/plpgsql.sgml