This gives us the ability to define system-wide definitions for specific Hosts, and their options.
For example, with this in pillar:
```
# this is the place for host-wide SSH config
ssh_config:
...
Hosts:
# this simplifies cloning with custom params
# eg: git clone my-git:foo/bar
my-git:
User: git
HostName: git.example.com
Port: 2222
```
This would add a section in `/etc/ssh/ssh_config`:
```
Host my-git
User git
HostName git.example.com
Port 2222
```
