Add support of "%h" value in ssh_config and replace it by the host value

Right now when I have in my ssh_config or ~/.ssh/config an entry like:

```
Host web*
 HostName %h.example.com
 User gklein
 IdentityFile mykey.pem
```
NET::SSH try to connect %h.example.com, which is wrong

With this patch we automatically replace "%h" value by the value of Host used by the client 
If connection host value is web34 like:
```
ssh username@web34
```
NET::SSH try to connect web34.example.com, which is the normal behavior of ssh with "%h" value in the config file.