Hack to use the std::array support for boost::array.
Is limited as it currently exposes some 'using' bugs in SWIG.
For example, the type system fails to see that pointers to std::array
and pointers to boost::array are the same.
This approach saves having to maintain separate boost::array support.
The 'using' bug ought to be fixed, otherwise separate boost_array.i
files could be easily made from the std_array.i files.
Setting an STL container wrapper slice better matches the way Ruby
arrays work. The behaviour is now the same as Ruby arrays. The only
exception is the default value used when expanding a container
cannot be nil as this is not a valid type/value for C++ container
elements.
