This commit was manufactured by cvs2svn to create branch 'RC_1_31_0'.

svn path=/branches/RC_1_31_0/boost/boost/utility/; revision=21427
merged from trunk

svn path=/branches/RC_1_31_0/boost/boost/ref.hpp; revision=21530
Merged fixes from trunk to branch

svn path=/branches/RC_1_31_0/boost/libs/utility/; revision=21741
merged DM fixes from the main trunk

svn path=/branches/RC_1_31_0/boost/boost/detail/call_traits.hpp; revision=21934
When we have a compressed pair of two types that are the same, and both empty, then we must still have two distict objects in the pair.

svn path=/branches/RC_1_31_0/boost/boost/detail/compressed_pair.hpp; revision=21958
Added missing include <cstddef>

svn path=/branches/RC_1_31_0/boost/boost/detail/call_traits.hpp; revision=21993