Assign floating IPs to the correct fixed IP

[RuthDevlaeminck]

When there are multiple connections to the same network code will currently attempt to assign a floating ip to all of the fixed ip's on that network. Instead of assigning networks to a server pre-create the ports and then assign the ports to the server. This also allows for assigning the correct floating ip to the correct fixed ip.

[RuthDevlaeminck]

Code merged with issue-51 branch merge