Create a development branch for the hash library.

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

svn path=/branches/hash/boost/detail/shared_count.hpp; revision=39016
Merge from trunk.

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

svn path=/branches/hash/boost/detail/sp_counted_base.hpp; revision=39995