Fix buffer size determination.
Fixes #8082.

git-svn-id: http://svn.boost.org/svn/boost/trunk@83967 b8fc166d-592f-0410-95f2-cb63ce0dd405
geometry.index.rtree: added experimental nearest query iterator, rtree::qbegin() and rtree::qend() methods modified to support it, cosmetic change in spatial query iterator (addressof() instead of &)


git-svn-id: http://svn.boost.org/svn/boost/trunk@83968 b8fc166d-592f-0410-95f2-cb63ce0dd405
geometry.index: test - added test for experimental nearest query iterator, examples - added experimental nearest query iterator to benchmark.

git-svn-id: http://svn.boost.org/svn/boost/trunk@83969 b8fc166d-592f-0410-95f2-cb63ce0dd405
Added some more parameter to configure libpng on how to write images.

git-svn-id: http://svn.boost.org/svn/boost/trunk@83970 b8fc166d-592f-0410-95f2-cb63ce0dd405
geometry.index.rtree: removed unused variable

git-svn-id: http://svn.boost.org/svn/boost/trunk@83971 b8fc166d-592f-0410-95f2-cb63ce0dd405
geometry.index.rtree: fixed error in nearest query iterative visitor.

git-svn-id: http://svn.boost.org/svn/boost/trunk@83972 b8fc166d-592f-0410-95f2-cb63ce0dd405
geometry.index.rtree: unclear condition in nearest query iterative visitor replaced by shorter and cleaner one.

git-svn-id: http://svn.boost.org/svn/boost/trunk@83973 b8fc166d-592f-0410-95f2-cb63ce0dd405
geometry.index.rtree: removed unneeded prune_nodes() method from nearest query visitor.

git-svn-id: http://svn.boost.org/svn/boost/trunk@83974 b8fc166d-592f-0410-95f2-cb63ce0dd405
geometry.index.rtree: added condition in nearest query iterative visitor for safety reasons.

git-svn-id: http://svn.boost.org/svn/boost/trunk@83975 b8fc166d-592f-0410-95f2-cb63ce0dd405