YCbCr color space.

git-svn-id: http://svn.boost.org/svn/boost/trunk@83495 b8fc166d-592f-0410-95f2-cb63ce0dd405
Added some comments.

git-svn-id: http://svn.boost.org/svn/boost/trunk@83500 b8fc166d-592f-0410-95f2-cb63ce0dd405
First version of subsampled_image.

git-svn-id: http://svn.boost.org/svn/boost/trunk@83501 b8fc166d-592f-0410-95f2-cb63ce0dd405
Some subsampled_image tests.

git-svn-id: http://svn.boost.org/svn/boost/trunk@83502 b8fc166d-592f-0410-95f2-cb63ce0dd405
Thread: protect some tests with BOOST_THREAD_PROVIDES_VARIADIC_THREAD.

git-svn-id: http://svn.boost.org/svn/boost/trunk@83503 b8fc166d-592f-0410-95f2-cb63ce0dd405
add missing history information

git-svn-id: http://svn.boost.org/svn/boost/trunk@83504 b8fc166d-592f-0410-95f2-cb63ce0dd405