-- made string_length return an unsigned int instead of int in order to

   avoid warnings about comparing singed with unsigned values


[SVN r29880]

libs/spirit

@@ -1 +1 @@
-Subproject commit 3204c8fc5ba5b72d8b756b35c2a9730e8b1ef717
+Subproject commit 463fb38aaa91cbaca2695c17c550efcf6eed52d2