Replace GameLogic.getScore with listen/subscribe.

[soulne4ny]

https://github.com/yarcat/chemistry-lines/commit/ce2161163cc303d1152fb714cd23e146e8bf1fec#commitcomment-2315909

[soulne4ny]

There are some problems in https://github.com/yarcat/chemistry-lines/commit/ec5530a15cdfd31c60ff359679e390ca0203f5ec:

• GameLogic still has getScorer().
• Each Scorer.update() implementation has to notify listener by itself.
• The score UI box is not auto-updated before the first move. SwingUIFactory has to make a fake call onScoreChange().

[soulne4ny]

Please, review https://github.com/yarcat/chemistry-lines/commit/ec5530a15cdfd31c60ff359679e390ca0203f5ec.

[yarcat]

1. Let's get rid of getScorer() by allowing to inject scorer into game logic (in this case creator will know the instance, and will be able to set/add listener(s))

2. Base scorer can have implementation of update()

   public void update(CompoundReference ref) {
    String value = updateAndGetNewScore(ref);
    for (ScoreListener listener : mListeners) {
      listener.onScoreUpdate(value);
    }
   }

   or smth similar. In this case implementations will have to override updateAndGetNewScore, and listeners will be notified automagically.

3. As we already discussed, this can be done through an init() call.

[soulne4ny]

We have following debts left in the issue:

• ScoreContainer. To replace it with several separate score UI items it requires to allow multiple subscribers. I'd like to make it generic, but not right now.
• GameLogic.getScorer() still there too. Moving scorer out of GameLogic requires keeping multiple GameListerner. See above.

[soulne4ny]

Please, review.