tuned doc comment

--- a/src/Doc/Datatypes/Datatypes.thy	Wed Apr 23 10:23:27 2014 +0200
+++ b/src/Doc/Datatypes/Datatypes.thy	Wed Apr 23 10:23:27 2014 +0200
@@ -2708,8 +2708,6 @@
 %* in a locale, cannot use locally fixed types (because of limitation in typedef)?
 %
 % *names of variables suboptimal
-%
-% * in a locale, size is half broken
 *}
 *)