Converted all devarianted_xxx classes to the new resolve_variant approach.

git-svn-id: http://svn.boost.org/svn/boost/trunk@86345 b8fc166d-592f-0410-95f2-cb63ce0dd405
Previous commit failed for types with an extended exponent range - use logarithms rather than assuming the result is zero.

git-svn-id: http://svn.boost.org/svn/boost/trunk@86346 b8fc166d-592f-0410-95f2-cb63ce0dd405
Update 1.55 release notes, regenerate docs.

git-svn-id: http://svn.boost.org/svn/boost/trunk@86347 b8fc166d-592f-0410-95f2-cb63ce0dd405