Initial UnknownHostException is Unrecoverable

The `RawSocketSender` takes a host and port in its constructor and coverts these into an `InetSocketAddress`, which tries to resolve the hostname. On `RawSocketSender` connect this `InetSocketAddress` is used to reconnect, but if it wasn't resolved during fluent-logger init then it will fail over and over. The code snipped from `RawSocketSender` is below:

``` java
public RawSocketSender(String host, int port, int timeout, int bufferCapacity, Reconnector reconnector) {
msgpack = new MessagePack();
msgpack.register(Event.class, Event.EventTemplate.INSTANCE);
pendings = ByteBuffer.allocate(bufferCapacity);
server = new InetSocketAddress(host, port); // Create InetSocketAddress on init
this.reconnector = reconnector;
name = String.format("%s_%d_%d_%d", host, port, timeout, bufferCapacity);
this.timeout = timeout;
}

private void connect() throws IOException {
try {
socket = new Socket();
socket.connect(server, timeout); // Reconnection uses pre-resolved server field
out = new BufferedOutputStream(socket.getOutputStream());
} catch (IOException e) {
throw e;
}
}
```

This issue comes up when using the fluent-logger in a highly dynamic environment (like on Docker Swarm) where apps may come up before a DNS entry in Consul is even resolvable. It also means that during failover of a Fluent host (triggering a DNS change) the then failing socket connection will always try the old Fluent host IP and never re-resolve the DNS entry.

My recommendation is to store the Fluent host and port as private fields within the `RawSocketSender`, not a resolved `InetSocketAddress` (now stored as `this.server`) and create a new `InetSocketAddress` on every socket connection.

I understand there will be performance implications of this and am happy to submit a PR, but wanted to bring it up in an issue in case there were reasons for implementing the `RawSocketSender` the current way.

Start with the RawSocketSender constructor and its connect() method, especially how the server address is stored and reused. Verify the behavior when the initial hostname lookup fails and when DNS changes during failover; done means reconnection uses the current hostname resolution rather than an old resolved address.

Written by the indexing model from the issue text.