another round of user interface cleanups

doc/src/sgml/ref/createlang.sgml

doc/src/sgml/ref/droplang.sgml

src/bin/Makefile

src/bin/initdb/initdb.sh

src/bin/initlocation/initlocation.sh

src/bin/ipcclean/ipcclean.sh

src/bin/pg_dump/pg_dump.c

src/bin/pg_id/Makefile

src/bin/pg_id/pg_id.c

src/bin/psql/common.c

src/bin/psql/help.c

src/bin/psql/startup.c

src/bin/scripts/createdb

src/bin/scripts/createlang.sh

src/bin/scripts/createuser

src/bin/scripts/dropdb

src/bin/scripts/droplang

src/bin/scripts/dropuser

src/bin/scripts/vacuumdb