Added is_copy_constructible triat implementation and tests (refs #8802)

git-svn-id: http://svn.boost.org/svn/boost/trunk@84987 b8fc166d-592f-0410-95f2-cb63ce0dd405
Improved rvalues move support for elements of circular_buffer (refs #7888): 
* move_if_noexcept uses is_copy_constructible trait
* more tests, tests are now more strict
* linearize() now works with move-only types

git-svn-id: http://svn.boost.org/svn/boost/trunk@84988 b8fc166d-592f-0410-95f2-cb63ce0dd405
removed duplicate typedef.

git-svn-id: http://svn.boost.org/svn/boost/trunk@84989 b8fc166d-592f-0410-95f2-cb63ce0dd405
Set compiler symbol indicating an older libpng version.

git-svn-id: http://svn.boost.org/svn/boost/trunk@84990 b8fc166d-592f-0410-95f2-cb63ce0dd405
Improved rvalues move support for elements of circular_buffer (refs #7888): 
* set_capacity and rset_capacity now work with move-only types if move constructor of type marked with `noexcept`
* force placement ::new usage
* minor optimizations (move values in more cases)
* more tests

git-svn-id: http://svn.boost.org/svn/boost/trunk@84991 b8fc166d-592f-0410-95f2-cb63ce0dd405
Fixes #8793

git-svn-id: http://svn.boost.org/svn/boost/trunk@84993 b8fc166d-592f-0410-95f2-cb63ce0dd405
Add missing delete and additional checks in intermodule singleton code

git-svn-id: http://svn.boost.org/svn/boost/trunk@84994 b8fc166d-592f-0410-95f2-cb63ce0dd405