#562 - added backup strategy to settings

...e/deadlocker8/budgetmaster/backup/AutoBackupStrategy.java

...va/de/deadlocker8/budgetmaster/backup/AutoBackupTime.java

...a/de/deadlocker8/budgetmaster/services/BackupService.java

.../de/deadlocker8/budgetmaster/services/HelpersService.java

...n/java/de/deadlocker8/budgetmaster/settings/Settings.java

...deadlocker8/budgetmaster/settings/SettingsController.java

...de/deadlocker8/budgetmaster/settings/SettingsService.java

.../deadlocker8/budgetmaster/settings/SettingsValidator.java

src/main/java/de/deadlocker8/budgetmaster/utils/Strings.java

src/main/resources/languages/base_de.properties

src/main/resources/languages/base_en.properties

src/main/resources/templates/settings/settings.ftl