#605 Logger - name methods after their log level

- Remove separate print stacktrace method
- Log level into the log similar to console output

src/main/java/fr/xephi/authme/process/email/AsyncAddEmail.java

@@ -47,7 +47,7 @@ public class AsyncAddEmail implements AsynchronousProcess {
                     playerCache.updatePlayer(auth);
                     service.send(player, MessageKey.EMAIL_ADDED_SUCCESS);
                 } else {
-                    ConsoleLogger.showError("Could not save email for player '" + player + "'");
+                    ConsoleLogger.warning("Could not save email for player '" + player + "'");
                     service.send(player, MessageKey.ERROR);
                 }
             }

src/main/java/fr/xephi/authme/process/login/AsynchronousLogin.java

@@ -204,7 +204,7 @@ public class AsynchronousLogin implements AsynchronousProcess {
                 }
             }
         } else {
-            ConsoleLogger.showError("Player " + name + " wasn't online during login process, aborted... ");
+            ConsoleLogger.warning("Player " + name + " wasn't online during login process, aborted... ");
         }
     }