#831 Cleanup, finalization

- Handle AsyncPlayerPreLoginEvent in main PlayerListener class: Spigot emits it in offline mode, whereas offline CraftBukkit doesn't
- Remove listener for sync PlayerPreLoginEvent; not fired by offline CraftBukkit either
- Add warning when offline CraftBukkit is detected and single session setting is enabled

src/test/java/fr/xephi/authme/listener/BlockListenerTest.java

@@ -9,9 +9,6 @@ import org.mockito.InjectMocks;
 import org.mockito.Mock;
 import org.mockito.runners.MockitoJUnitRunner;
 
-import fr.xephi.authme.listener.BlockListener;
-import fr.xephi.authme.listener.ListenerService;
-
 import static org.mockito.BDDMockito.given;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
@@ -21,7 +18,7 @@ import static org.mockito.Mockito.verifyNoMoreInteractions;
  * Test for {@link BlockListener}.
  */
 @RunWith(MockitoJUnitRunner.class)
-public class AuthMeBlockListenerTest {
+public class BlockListenerTest {
 
     @InjectMocks
     private BlockListener listener;

src/test/java/fr/xephi/authme/listener/ListenerConsistencyTest.java

@@ -1,14 +1,6 @@
 package fr.xephi.authme.listener;
 
 import com.google.common.collect.Sets;
-
-import fr.xephi.authme.listener.BlockListener;
-import fr.xephi.authme.listener.EntityListener;
-import fr.xephi.authme.listener.PlayerListener;
-import fr.xephi.authme.listener.PlayerListener16;
-import fr.xephi.authme.listener.PlayerListener18;
-import fr.xephi.authme.listener.ServerListener;
-
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.EventPriority;
 import org.junit.Test;
@@ -36,7 +28,7 @@ public final class ListenerConsistencyTest {
         "PlayerListener#onPlayerJoin", "PlayerListener#onPlayerLogin",
         "PlayerListener#onPlayerQuit", "ServerListener#onPluginDisable",
         "ServerListener#onServerPing", "ServerListener#onPluginEnable",
-        "PlayerListener#onJoinMessage", "PlayerListener#onLoginSingleSession");
+        "PlayerListener#onJoinMessage", "PlayerListener#onAsyncPreLogin");
 
     @Test
     public void shouldSetIgnoreCancelledToTrue() {

src/test/java/fr/xephi/authme/listener/ListenerServiceTest.java

@@ -6,7 +6,6 @@ import ch.jalu.injector.testing.InjectDelayed;
 import fr.xephi.authme.cache.auth.PlayerCache;
 import fr.xephi.authme.datasource.DataSource;
 import fr.xephi.authme.hooks.PluginHooks;
-import fr.xephi.authme.listener.ListenerService;
 import fr.xephi.authme.settings.Settings;
 import fr.xephi.authme.settings.properties.RegistrationSettings;
 import fr.xephi.authme.util.ValidationService;

src/test/java/fr/xephi/authme/listener/OnJoinVerifierTest.java

@@ -4,8 +4,6 @@ import fr.xephi.authme.AntiBot;
 import fr.xephi.authme.TestHelper;
 import fr.xephi.authme.cache.auth.PlayerAuth;
 import fr.xephi.authme.datasource.DataSource;
-import fr.xephi.authme.listener.FailedVerificationException;
-import fr.xephi.authme.listener.OnJoinVerifier;
 import fr.xephi.authme.output.MessageKey;
 import fr.xephi.authme.output.Messages;
 import fr.xephi.authme.permission.PermissionsManager;

src/test/java/fr/xephi/authme/util/ServerUtilsTest.java

@@ -0,0 +1,19 @@
+package fr.xephi.authme.util;
+
+import org.junit.Test;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test for {@link ServerUtils}.
+ */
+public class ServerUtilsTest {
+
+    @Test
+    public void shouldReturnTrueForSpigotImplementation() {
+        // Spigot is a provided dependency of the project, so the ClassLoader knows about it
+        assertThat(ServerUtils.isSpigot(), equalTo(true));
+    }
+
+}