Better descriptions in pg_get_keywords(), consistent with the documentation

appendix on key words.  catdesc was originally intended as computer-readable,
but since we ended up adding catcode, we can have more elaborate descriptions.

src/backend/utils/adt/misc.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.65 2008/11/03 17:51:13 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.66 2008/12/05 13:41:20 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -344,19 +344,19 @@ pg_get_keywords(PG_FUNCTION_ARGS)
 		{
 			case UNRESERVED_KEYWORD:
 				values[1] = "U";
-				values[2] = _("Unreserved");
+				values[2] = _("unreserved");
 				break;
 			case COL_NAME_KEYWORD:
 				values[1] = "C";
-				values[2] = _("Column name");
+				values[2] = _("unreserved (cannot be function or type name)");
 				break;
 			case TYPE_FUNC_NAME_KEYWORD:
 				values[1] = "T";
-				values[2] = _("Type or function name");
+				values[2] = _("reserved (can be function or type name)");
 				break;
 			case RESERVED_KEYWORD:
 				values[1] = "R";
-				values[2] = _("Reserved");
+				values[2] = _("reserved");
 				break;
 			default:			/* shouldn't be possible */
 				values[1] = NULL;