API Changes

RequestDispatcher v.1.4

• ZmqAdapter no longer part of external API:
  dp.registerServiceAdapter(String.class, new ZmqAdapter(ctx, channel));
  now reads:
  dp.registerService(String.class, channel);
• Removed String identifier for services.
  Need to have separate request classes for all registered services.
  removed dispatcher.setDefaultService()
• Dispatcher objects handles ZMC.Context object.