dxFeed API changes

* BUG FIX: Potential reordering of events when multi-threaded executor is used

* Introduce DXEndpoint class for managing of DXFeed (connect/disconnect/close). DXFeed.createConnectedFeed(…) is now deprecated. Use DXEndpoint.create().connect(…).getFeed() instead.

* Introduce DXPublisher to publish events.

* New fields added into Profile event: “StatusReason”, “HaltStartTime”, “HaltEndTime”.

* Schedule API: add more methods for searching.

* Schedule API: add reset time property.

* TimeAndSale.isTrade() property was renamed into isValidTick().  (Old getter & setter were deprecated and will be removed in future.)

+ Lots of internal changes for QDS infrastructure components