Message style revisions

src/backend/access/heap/heapam.c

src/backend/access/transam/xlog.c

src/backend/catalog/dependency.c

src/backend/commands/tablecmds.c

src/backend/executor/spi.c

src/backend/libpq/auth.c

src/backend/libpq/hba.c

src/backend/main/main.c

src/backend/port/win32/security.c

src/backend/port/win32/signal.c

src/backend/postmaster/bgwriter.c

src/backend/postmaster/postmaster.c

src/backend/postmaster/syslogger.c

src/backend/tcop/postgres.c

src/backend/utils/adt/misc.c

src/backend/utils/misc/guc.c

src/bin/initdb/initdb.c

src/bin/pg_ctl/pg_ctl.c

src/bin/pg_dump/pg_restore.c

src/bin/psql/describe.c