Merge from trunk.

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

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

svn path=/branches/hash/boost/pending/detail/disjoint_sets.hpp; revision=39995
Another merge.

svn path=/branches/hash/boost/pending/disjoint_sets.hpp; revision=40001
Merge from trunk.

svn path=/branches/hash/boost/pending/detail/disjoint_sets.hpp; revision=40260
Merge from trunk. Including floating point hash tweaks.

svn path=/branches/hash/boost/pending/detail/disjoint_sets.hpp; revision=40266