Fixed #126 - Add English localization

src/de/deadlocker8/budgetmaster/logic/CategoryHandler.java

src/de/deadlocker8/budgetmaster/main/Main.java

...adlocker8/budgetmaster/resources/languages/_de.properties

...adlocker8/budgetmaster/resources/languages/_en.properties

...ocker8/budgetmaster/ui/controller/SettingsController.java

src/de/deadlocker8/budgetmaster/ui/fxml/ChartTab.fxml

src/de/deadlocker8/budgetmasterserver/main/Main.java

src/de/deadlocker8/budgetmasterserver/main/_de.properties