use ice_not<> instead of logical not "!" to work around problems with

early EDG (for example, IRIX CC and Compaq C++)


[SVN r9255]

libs/type_traits

@@ -1 +1 @@
-Subproject commit 7b57ce4392c5a3dcaa4de591f5ca591bf80e18ab
+Subproject commit ab2358913cc21643f0e0f0c2d32f832d17c32f49