Memory leaks on dUSE_MALLOC_FOR_ALLOCA

[Daniel K. O.]

Original issue here: http://sourceforge.net/p/opende/bugs/50/

In general, alloca() is not portable, and causes fatal errors when allocation fails. It's better to replace them with automatic allocation (like std::vector).

This might require a custom aligned_allocator to use in such vectors. Eigen has an aligned_allocator for reference: http://eigen.tuxfamily.org/dox-devel/Memory_8h_source.html