mods to boost smart_ptr

* shared_array.hpp: svn [12241](https://isrsvn.usurf.usu.edu/trac/isr/changeset/12241/trunk/sdlExtern/include/boost/shared_array.hpp), [21777](https://isrsvn.usurf.usu.edu/trac/isr/changeset/21777#file13), [22215](https://isrsvn.usurf.usu.edu/trac/isr/changeset/22215)

boost 1.49
* [commit](https://github.com/smanders/boost-svn/commit/f72fdc3140a13ab989d954d7608626df933e672c) where we applied this to boost 1.49
* all boost 1.49 [patch commits](https://github.com/smanders/boost-svn/commits/sdl_1_49_0)

Maybe we don't need to apply this to 1.55? The
```cpp
template <class Y> friend class shared_array;
```
that we added in 1.49 is there in 1.55...