This commit was manufactured by cvs2svn to create branch 'mpl_v2_2'.

svn path=/branches/mpl_v2_2/boost/boost/signal.hpp; revision=18675
merge latest main trunk fixes

svn path=/branches/mpl_v2_2/boost/boost/last_value.hpp; revision=18769
Removed old branches.

svn path=/branches/mpl_v2_2/boost/boost/signal.hpp; revision=38550