griffon application can't show message.properties with utf8 encoding correctly by default

gistfile1.txt

check the source code as described here: https://stackoverflow.com/a/4660195/828181, it's because the PropertiesReader use the default 'ISO-8859-1' encoding.
the solution is binding your own PropertiesReader and read the stream as utf-8:

public class PropertiesReader extends griffon.util.PropertiesReader {
    @Nonnull
    public Properties load(@Nonnull InputStream stream) throws IOException {
        Properties p = new Properties();
        p.load(new InputStreamReader(stream, "UTF-8"));
        return this.processProperties(p);
    }
}

and in the ApplicationModule:

bind(griffon.util.PropertiesReader.class)
                .to(PropertiesReader.class)
                .asSingleton();