v0.6

updated InitGUI
updated UserAlreadExistsException to include error message when default
constructor is called
updated messages_fr/messages_en/messages_nl to include:
maptranslation, InitGUItranslation, titleTranslation
updated Startup.java to construct a new LanguageGUI.java which then
constructs InitGUI.java

changed params of LanguageGUI.java and InitGUI.java constructors to
include DomainController to call startGame(String) with given String

deprecated:
InitialisationJigloo.java: temp. included for look-up purposes
ApplicationController.java: already deleted