Added MessageDecoder interface. All decoder implement this.

Added DecoderFactory. This creates an appropriate decoder based on a MessageType.
BoatActionDecoder implements MessageDecoder.
BoatLocationDecoder implements MessageDecoder.
HeartBeatDecoder implements MessageDecoder.
JoinAcceptance implements MessageDecoder.
RaceStatusDecoder implements MessageDecoder.
RequestToJoinDecoder implements MessageDecoder.
XMLMessageDecoder implements MessageDecoder.
Refactored CourseWind decoder/encoder. CourseWind decoder/encoder is for an individual CourseWind.
CourseWinds decoder/encoder is for the combined message from the API.
Documented BoatAction, and it now contains a BoatActionEnum instead of a byte.
Refactored CourseWind and CourseWinds classes. They now expose correct units, instead of packed units.
Added CourseWindDecoderTest, and updated CourseWindsDecoderTest.
issue #35 #36
#story[1095]

racevisionGame/src/main/java/visualiser/gameController/ControllerServer.java

@@ -2,6 +2,7 @@ package visualiser.gameController;
 
 import network.BinaryMessageDecoder;
 import network.MessageDecoders.BoatActionDecoder;
+import network.Messages.BoatAction;
 import network.Messages.Enums.BoatActionEnum;
 import visualiser.gameController.Keys.ControlKey;
 import visualiser.gameController.Keys.KeyFactory;
@@ -47,9 +48,10 @@ public class ControllerServer implements Runnable {
                 if (inputStream.available() > 0) {
                     inputStream.read(message);
                     BinaryMessageDecoder encodedMessage = new BinaryMessageDecoder(message);
-                    BoatActionDecoder boatActionDecoder = new BoatActionDecoder(encodedMessage.getMessageBody());
-                    BoatActionEnum decodedMessage = boatActionDecoder.getBoatAction();
-                    System.out.println("Received key: " + decodedMessage);
+                    BoatActionDecoder boatActionDecoder = new BoatActionDecoder();
+                    boatActionDecoder.decode(encodedMessage.getMessageBody());
+                    BoatAction boatAction = boatActionDecoder.getMessage();
+                    System.out.println("Received key: " + boatAction.getBoatAction());
                 }
             } catch (IOException e) {
                 e.printStackTrace();