std.allocator ready for some abuse

[Namespace]

>> Because Array!int looks a lot more ugly than such a nice thing 
>> as int[].
>> And if it is possible to change the allocator for some arrays, 
>> why
>> shouldn't we implement it?
>> The default allocator would stay the GC allocator. So if you 
>> don't want
>> to swap the allocator of your arrays, don't do it.
>
> Maintaining per-array-object allocators could be quite 
> expensive. Two other possibilities are keeping one allocators 
> for all array of a given type and of course keeping a global 
> allocator for all arrays.
>
> Andrei

Sounds also nice. As long as you can customize the way built-in 
arrays allocate, I'm fine with that. :)