Merged Boost.Graph, Boost.Graph.Parallel, and Boost.PropertyMap changes from Boost trunk

git-svn-id: http://svn.boost.org/svn/boost/branches/release@85813 b8fc166d-592f-0410-95f2-cb63ce0dd405
Thread: merge from trunk to fix 8070 and possibly 7461.

git-svn-id: http://svn.boost.org/svn/boost/branches/release@85815 b8fc166d-592f-0410-95f2-cb63ce0dd405