Logic for FoundCommandResult.Status / Add tests for CommandHandler

- Fix other tests
- Add logic for smaller pending FIXME's

src/test/java/fr/xephi/authme/command/executable/email/AddEmailCommandTest.java

@@ -11,6 +11,7 @@ import org.junit.Test;
 import org.mockito.Mockito;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
@@ -52,7 +53,7 @@ public class AddEmailCommandTest {
         AddEmailCommand command = new AddEmailCommand();
 
         // when
-        command.executeCommand(sender, new ArrayList<String>());
+        command.executeCommand(sender, Arrays.asList("mail@example", "other_example"));
 
         // then
         verify(authMeMock).getManagement();