LDEV-4402 Substitute Gson and Apache JSON with JacksonJackson is a top JSON library shipped with WF10.Apache JSON resides in an ancient library which we do not need foranything else.We use GSon only for serializing Java objects to JSON, which Jackson cando too.
LDEV-4092: Date passed back by server was reconverting time for Daylight Saving, making it an hour out, as the convertToStringForJSON takes the timezone into account. Therefore convert the already timezone converted time (which gets converted back again) rather than the original time.
LDEV-4092: Support the server supplying a localised date string for the submission deadline (datetimepicker does not have localisation of the format, just the language).