Allow setting Delivery Controller AdminAddress as parameter

Currently, the utility will only look at `localhost` for the Delivery Controller address. If you run the utility on a machine that is _not_ a Delivery Controller, you get this error:

```
System.Management.Automation.CmdletInvocationException
HResult=0x80131501
Message=Failed to connect to back-end server 'localhost' on port 80 using binding WSHttp. The server may be off-line or may not be running the appropriate service
```

I worked around this by adding the `AdminAddress` parameter to the PowerShell calls:

```csharp
ps.AddParameter("AdminAddress", "DeliveryController01.example.com");
```

It would be great if you could specify the Delivery Controller address, either in the GUI or as a command line parameter.