Added textbox which receives info on what is happening (files being
downloaded, failures that don't close the updater).
Added more information to error messages.
Added a retry option/dialog box for JSON file download failure, will
attempt to download the file until user cancels it.
Added German language translations for all info/error messages.
Language switching is based on user's OS language choice and is handled
by the updater itself to avoid requiring a separate dll for
translations.