#598 - added converters for backup models v6 to internal entities

...in/java/de/deadlocker8/budgetmaster/accounts/Account.java

...java/de/deadlocker8/budgetmaster/categories/Category.java

.../de/deadlocker8/budgetmaster/database/DatabaseParser.java

...de/deadlocker8/budgetmaster/database/model/Converter.java

...ker8/budgetmaster/database/model/v5/BackupAccount_v5.java

...er8/budgetmaster/database/model/v5/BackupDatabase_v5.java

...er8/budgetmaster/database/model/v6/BackupDatabase_v6.java

...tmaster/database/model/v6/converter/AccountConverter.java

...master/database/model/v6/converter/CategoryConverter.java

...getmaster/database/model/v6/converter/ChartConverter.java

...getmaster/database/model/v6/converter/ImageConverter.java

...master/database/model/v6/converter/TemplateConverter.java

...ter/database/model/v6/converter/TransactionConverter.java

src/main/java/de/deadlocker8/budgetmaster/images/Image.java

...in/java/de/deadlocker8/budgetmaster/utils/ProvidesID.java