Wave: merging from trunk

git-svn-id: http://svn.boost.org/svn/boost/branches/release@85646 b8fc166d-592f-0410-95f2-cb63ce0dd405
Merging latest spin_wait improvements + unused typedef removal.


git-svn-id: http://svn.boost.org/svn/boost/branches/release@85653 b8fc166d-592f-0410-95f2-cb63ce0dd405
Merged recent changes from trunk.

git-svn-id: http://svn.boost.org/svn/boost/branches/release@85657 b8fc166d-592f-0410-95f2-cb63ce0dd405