#598 - suppress warnings and add special type field

src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupDatabase_v4.java

 package de.deadlocker8.budgetmaster.database.model.v4;
 
 import de.deadlocker8.budgetmaster.database.InternalDatabase;
+import de.deadlocker8.budgetmaster.database.JSONIdentifier;
 import de.deadlocker8.budgetmaster.database.model.BackupDatabase;
 import de.deadlocker8.budgetmaster.database.model.Upgradeable;
 import de.deadlocker8.budgetmaster.database.model.v5.BackupDatabase_v5;
@@ -10,6 +11,10 @@ import java.util.List;
 
 public class BackupDatabase_v4 implements BackupDatabase
 {
+	@SuppressWarnings("unused")
+	private final String TYPE = JSONIdentifier.BUDGETMASTER_DATABASE.toString();
+
+	@SuppressWarnings("FieldCanBeLocal")
 	private final int VERSION = 4;
 
 	private List<BackupCategory_v4> categories;

src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupDatabase_v5.java

@@ -4,6 +4,7 @@ import de.deadlocker8.budgetmaster.accounts.Account;
 import de.deadlocker8.budgetmaster.categories.Category;
 import de.deadlocker8.budgetmaster.charts.Chart;
 import de.deadlocker8.budgetmaster.database.InternalDatabase;
+import de.deadlocker8.budgetmaster.database.JSONIdentifier;
 import de.deadlocker8.budgetmaster.database.model.BackupDatabase;
 import de.deadlocker8.budgetmaster.database.model.Converter;
 import de.deadlocker8.budgetmaster.database.model.v5.converter.*;
@@ -16,6 +17,10 @@ import java.util.List;
 
 public class BackupDatabase_v5 implements BackupDatabase
 {
+	@SuppressWarnings("unused")
+	private final String TYPE = JSONIdentifier.BUDGETMASTER_DATABASE.toString();
+
+	@SuppressWarnings("FieldCanBeLocal")
 	private final int VERSION = 5;
 
 	private List<BackupCategory_v5> categories;
@@ -124,7 +129,7 @@ public class BackupDatabase_v5 implements BackupDatabase
 	@Override
 	public int getVersion()
 	{
-		return this.VERSION;
+		return VERSION;
 	}
 
 	@Override