Switch the test to use std::stringstream, not std::ostrstream, since

the latter is deprecated and gcc warns whenever one tries to use it.


[SVN r23896]

libs/utility

@@ -1 +1 @@
-Subproject commit 35d3c03d19df09072fae886d78a6dd4f217b590f
+Subproject commit d5a5b84a408d1e4e303b48735612f5dba16f3aec