void doGiveHint(HanabiGame game, HttpServletRequest req, HttpServletResponse resp)
throws IOException, ServletException, HanabiException {
String target = req.getParameter("target");
String hint = req.getParameter("hint");
game.giveHint(target, hint);
JsonGenerator out = new JsonFactory().createJsonGenerator(resp.getOutputStream());
out.writeStartObject();
out.writeStringField("message", "hint given; " + game.hintsLeft + " hints left");
out.writeEndObject();
out.close();
}
