Copy hash library from 1.34.1 over trunk.

For the first merge with the release branch, I only want to include some of the
changes I've been working on (fixes and some trivial changes), so I'm starting
again from 1.34.1.


[SVN r38873]

libs/functional

@@ -1 +1 @@
-Subproject commit 08d38c1e39cbeaaf30004c53a7460c397b75d7a3
+Subproject commit ff43cf2784d55c10552f93320ed8915589599579