Boost workaround's shared_xxx stuff now matches boosts documented API.
Add shared_array.hpp to boost workaround (forgot to commit it when I added shared_ptr.hpp).
git-svn-id: https://assimp.svn.sourceforge.net/svnroot/assimp/trunk@668 67173fc5-114c-0410-ac8e-9d2fd5bffc1f