Revert the default toast compression strategy to the former behavior

where there's no limit on the size of datum we'll try to compress.
Other 8.4 tweaks to the behavior remain in place.  Per discussion.

src/backend/utils/adt/pg_lzcompress.c

@@ -166,7 +166,7 @@
  *
  * Copyright (c) 1999-2009, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/backend/utils/adt/pg_lzcompress.c,v 1.32 2009/01/01 17:23:49 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/pg_lzcompress.c,v 1.33 2009/01/06 15:51:38 tgl Exp $
  * ----------
  */
 #include "postgres.h"
@@ -211,7 +211,7 @@ typedef struct PGLZ_HistEntry
  */
 static const PGLZ_Strategy strategy_default_data = {
 	32,				/* Data chunks less than 32 bytes are not compressed */
-	1024 * 1024,	/* Data chunks over 1MB are not compressed either */
+	INT_MAX,		/* No upper limit on what we'll try to compress */
 	25,				/* Require 25% compression rate, or not worth it */
 	1024,			/* Give up if no compression in the first 1KB */
 	128,			/* Stop history lookup if a match of 128 bytes is found */