First swing at converting from racoon to StrongSWAN.
It allows to use existing configurations on xml to generate StrongSWAN configurations.
So its only IKEv1

* Missing support for dynamic ips(hostnames)
  - resolver plugin of StrongSWAN needs to be configured in strongswan.conf
* Authentication plugin with pfSense authentication framework
  - New plugin almost completed

* More testing hence this being pushed now to have more broader look

TODO
* Integrate IKEv2
* Move dynamic IP allocation to an SQLite backend
* Provide more options in authenticating as a client(initiator)
* Restrict interfaces where StrongSWAN listens for incoming connections to only those configured

FUTUTE
* Move all configuration to SQLite backend
* Integrate more authentication scenarios of IKEv2