#761 Restore permission group in sync with limbo players

- Couple AuthGroupHandler closer to the LimboService: whenever a limbo player is restored, the auth group should be restored as well. This fixes some consistency issues.
- Move AuthGroupHandler into limbo package and make it package-private
- Change permission handler to skip any empty groups (prevents odd command output e.g. for BukkitPermissions)

src/test/java/fr/xephi/authme/process/unregister/AsynchronousUnregisterTest.java

@@ -7,8 +7,6 @@ import fr.xephi.authme.data.limbo.LimboService;
 import fr.xephi.authme.datasource.DataSource;
 import fr.xephi.authme.events.AbstractUnregisterEvent;
 import fr.xephi.authme.message.MessageKey;
-import fr.xephi.authme.permission.AuthGroupHandler;
-import fr.xephi.authme.permission.AuthGroupType;
 import fr.xephi.authme.security.PasswordSecurity;
 import fr.xephi.authme.security.crypts.HashedPassword;
 import fr.xephi.authme.service.BukkitService;
@@ -62,8 +60,6 @@ public class AsynchronousUnregisterTest {
     @Mock
     private TeleportationService teleportationService;
     @Mock
-    private AuthGroupHandler authGroupHandler;
-    @Mock
     private CommandManager commandManager;
 
     @BeforeClass
@@ -90,7 +86,7 @@ public class AsynchronousUnregisterTest {
         // then
         verify(service).send(player, MessageKey.WRONG_PASSWORD);
         verify(passwordSecurity).comparePassword(userPassword, password, name);
-        verifyZeroInteractions(dataSource, limboService, authGroupHandler, teleportationService, bukkitService);
+        verifyZeroInteractions(dataSource, limboService, teleportationService, bukkitService);
         verify(player, only()).getName();
     }
 
@@ -119,7 +115,6 @@ public class AsynchronousUnregisterTest {
         verify(dataSource).removeAuth(name);
         verify(playerCache).removePlayer(name);
         verify(teleportationService).teleportOnJoin(player);
-        verify(authGroupHandler).setGroup(player, AuthGroupType.UNREGISTERED);
         verify(bukkitService).scheduleSyncTaskFromOptionallyAsyncTask(any(Runnable.class));
         verifyCalledUnregisterEventFor(player);
         verify(commandManager).runCommandsOnUnregister(player);
@@ -150,7 +145,6 @@ public class AsynchronousUnregisterTest {
         verify(dataSource).removeAuth(name);
         verify(playerCache).removePlayer(name);
         verify(teleportationService).teleportOnJoin(player);
-        verify(authGroupHandler).setGroup(player, AuthGroupType.UNREGISTERED);
         verify(bukkitService).scheduleSyncTaskFromOptionallyAsyncTask(any(Runnable.class));
         verifyCalledUnregisterEventFor(player);
         verify(commandManager).runCommandsOnUnregister(player);
@@ -179,7 +173,6 @@ public class AsynchronousUnregisterTest {
         verify(passwordSecurity).comparePassword(userPassword, password, name);
         verify(dataSource).removeAuth(name);
         verify(playerCache).removePlayer(name);
-        verify(authGroupHandler).setGroup(player, AuthGroupType.UNREGISTERED);
         verifyZeroInteractions(teleportationService, limboService);
         verify(bukkitService, never()).runTask(any(Runnable.class));
         verifyCalledUnregisterEventFor(player);
@@ -207,7 +200,7 @@ public class AsynchronousUnregisterTest {
         verify(passwordSecurity).comparePassword(userPassword, password, name);
         verify(dataSource).removeAuth(name);
         verify(service).send(player, MessageKey.ERROR);
-        verifyZeroInteractions(teleportationService, authGroupHandler, bukkitService);
+        verifyZeroInteractions(teleportationService, bukkitService);
     }
 
     @Test
@@ -232,7 +225,7 @@ public class AsynchronousUnregisterTest {
         verify(passwordSecurity).comparePassword(userPassword, password, name);
         verify(dataSource).removeAuth(name);
         verify(playerCache).removePlayer(name);
-        verifyZeroInteractions(teleportationService, authGroupHandler);
+        verifyZeroInteractions(teleportationService);
         verifyCalledUnregisterEventFor(player);
     }
 
@@ -256,7 +249,6 @@ public class AsynchronousUnregisterTest {
         verify(dataSource).removeAuth(name);
         verify(playerCache).removePlayer(name);
         verify(teleportationService).teleportOnJoin(player);
-        verify(authGroupHandler).setGroup(player, AuthGroupType.UNREGISTERED);
         verify(bukkitService).scheduleSyncTaskFromOptionallyAsyncTask(any(Runnable.class));
         verifyCalledUnregisterEventFor(player);
         verify(commandManager).runCommandsOnUnregister(player);
@@ -274,7 +266,7 @@ public class AsynchronousUnregisterTest {
         // then
         verify(dataSource).removeAuth(name);
         verify(playerCache).removePlayer(name);
-        verifyZeroInteractions(authGroupHandler, teleportationService);
+        verifyZeroInteractions(teleportationService);
         verifyCalledUnregisterEventFor(null);
     }
 
@@ -291,7 +283,7 @@ public class AsynchronousUnregisterTest {
         // then
         verify(dataSource).removeAuth(name);
         verify(service).send(initiator, MessageKey.ERROR);
-        verifyZeroInteractions(playerCache, teleportationService, authGroupHandler, bukkitService);
+        verifyZeroInteractions(playerCache, teleportationService, bukkitService);
     }
 
     @SuppressWarnings("unchecked")