[Proposal] Auto Properties with private setters

[Proposal] Auto Properties with private setters
This C# code
```C#
public string Name { get; private set; }
```

corresponds to all this VB code:
```VB.NET
Dim _name As String
Public Property Name As String
Get
Return _name
End Get

Private Set(value As String)
_name = value
End Set
End Property
```

I suggest to use an attribute like this:
```VB.NET
Public Property Name As String
Public Property Age As Integer
```