[Cocoa-sharp] Cocoa namespace

[Andrew Brehm]

> > Using Cocoa;
> >
> > AppKit.whatever...
>
> Eh, I'd rather not have to type "AppKit." in addition to "NS". That's
> pretty heavy.

Using Cocoa.AppKit;

whatever...;

 > Also is AddressBook considered a part of Cocoa? What about WebKit? I
> don't think they are. And there will be future APIs from Apple. If we
> go with the Objective-C names such as "NSString" then I would prefer:
>
> using FoundationKit;
> using AppKit;
>

[...]

>
> This is analogous to .NET where you might say:
>
> using System;
> using System.Collections.Generic;
> using System.Windows.Forms;
>
> And it respects that not all things Objective-C are Cocoa.

That looks more like

Using Cocoa.AppKit;

then like

Using AppKit;