Create a development branch for the hash library.

svn path=/branches/hash/boost/asio.hpp; revision=38869
Merge from trunk.

svn path=/branches/hash/boost/asio/; revision=39287
Merge with the offending files removed.

svn path=/branches/hash/boost/asio/; revision=39995
Merge from trunk.

svn path=/branches/hash/boost/asio/; revision=40260
Merge from trunk. Including floating point hash tweaks.

svn path=/branches/hash/boost/asio/; revision=40266