Some extra decorations

[Paolo Carlini]

Jan Hubicka wrote:
> There are also many cases of virtual functions I am not sure what to do
> about and the problem with externally visible functions in headers
> (throw_allocator, bitmap_allocator and friends).
>   
Consider that allocators like bitmap_allocator and throw_allocator are
way, way, less important than other allocators, in particular, new, pool
and mt, from the performance / optimization point of view.

Paolo.