Created Unassigned: Dinamic Forwarding Socks5 Name Resolution via SSH [2589]

First of all. Sorry for my english. and thanks for all developers for making this amazing library.

https://sshnet.codeplex.com/SourceControl/latest#Renci.SshClient/Renci.SshNet/ForwardedPortDynamic.NET.cs

```
var length = stream.ReadByte();
addressBuffer = new byte[length];
stream.Read(addressBuffer, 0, addressBuffer.Length);

ipAddress = IPAddress.Parse(new ASCIIEncoding().GetString(addressBuffer));

//var hostName = new Common.ASCIIEncoding().GetString(addressBuffer);

//ipAddress = Dns.GetHostEntry(hostName).AddressList[0];
```
Accorrding to MSDN Documentation
> The GetHostEntry method queries a DNS server for the IP address that is associated with a host name or IP address.


If I use Dns.GetHostEntry I have two problem :
1. If I can't reach DNS Server (blocked via restricted firewall). and on chrome open google.com. SSH.NET will raise Socket Exception "no such host is known"
2. If I can reach DNS Server. name resolution will work. However this make DNS Leaks.

Please support SOCKS5 name resolution through SSH. Bitvise and Putty can do that.