Request: withArrayLength

[Simon Marlow]

> I think adding new (hierarchical) modules is the way to go for now.
> 
> 1) Hierarchical because it lets us use some nice clear
>    module naming style like:
> 
>      Foreign.NonStd.*
>    or
>      Foreign.Extension.*
> 
>    [I favour the former since the status of the lib is clearer.]

Not wanting to throw a spanner in the works, but we did agree not to use
these kinds of names back in the early days of the hierarhcical
libraries.  The general rule is to base names on the functionality
provided by the libraries only.

There are a few cases where we break the rules at the moment:
System.Posix and System.Win32 are a bit dubious, and there's
Unstable.Control.Monad.  But on the whole we're sticking to the policy,
and there are good reasons for doing so, so I vote not to introduce
Foreign.NonStd.

I'm beginning to think we should implement package versioning ASAP.  We
would need support for it in all compilers, though.

Cheers,
	Simon