broker/MapDBPersistentStore: Interfaces used for the Constructors

broker/IStore: Interface added for MapDBPersistentStore
broker/ProtocolProcessorBootstrapper: class loader for store added
broker/ISessionsStore#mapToGuid: moved to IMessagesStore
broker/ProtocolProcessorBootstrapper: getter used for SessionStore
broker/Server: getter for processor added
broker/ProtocolProcessor: getter added for Stores

perf/src/main/java/io/moquette/spi/impl/subscriptions/PerformanceTest.java

@@ -20,7 +20,6 @@ public class PerformanceTest {
     public static void main(String[] args) throws IOException, InterruptedException {
         SubscriptionsStore store = new SubscriptionsStore();
         MemoryStorageService memStore = new MemoryStorageService();
-        memStore.initStore();
         ISessionsStore aSessionsStore = memStore.sessionsStore();
         store.init(aSessionsStore);