Thread: first steps toward async(executor&, f).

git-svn-id: http://svn.boost.org/svn/boost/trunk@86327 b8fc166d-592f-0410-95f2-cb63ce0dd405
Added myself to the list of the authors (because of the timed functions).

git-svn-id: http://svn.boost.org/svn/boost/trunk@86330 b8fc166d-592f-0410-95f2-cb63ce0dd405
Default strategy placeholder class forgotten in previous commit.

git-svn-id: http://svn.boost.org/svn/boost/trunk@86332 b8fc166d-592f-0410-95f2-cb63ce0dd405
[geometry] fixed errors in overlay/follow.hpp related to proper usage of Linestring concept.

git-svn-id: http://svn.boost.org/svn/boost/trunk@86333 b8fc166d-592f-0410-95f2-cb63ce0dd405
[geometry] replaced size() and removed clear() call in overlay/follow.hpp.

git-svn-id: http://svn.boost.org/svn/boost/trunk@86334 b8fc166d-592f-0410-95f2-cb63ce0dd405