Nailgun initial arguments

This PR is for a discussion only. Do not apply it.

With these changes you should explicitly define initial arguments for the master node deployment. They should be placed to /etc/naily.facts file. Here they are:
```
$ cat /etc/naily.facts
mnbs_internal_ipaddress=10.20.0.2
mnbs_internal_netmask=255.255.255.0
mnbs_static_pool_start=10.20.0.130
mnbs_static_pool_end=10.20.0.250
mnbs_dhcp_pool_start=10.20.0.10
mnbs_dhcp_pool_end=10.20.0.120
mnbs_internal_interface=eth1
```