Add overloads of hash_value for more built in types. They're not strictly

needed and aren't in the original specifiction but they avoid a warning. See
ticket #1095 for details.


[SVN r38563]

libs/functional

@@ -1 +1 @@
-Subproject commit d8807048a688c004a0df33be146ce72afce41f8d
+Subproject commit 6753d4b5074fb502a439c2d3ec4f26974353af99