* Wait for global header before considering Stream is Armed
* Stream sequence finishes only when the series end header is received
* Stream::stop just sets state to Stopped, ignoring received data messages;
  add abort, which really interrupts Stream sequence
* Add EventCtrlObj, trigger Error Events on _read_zmq_messages exceptions
* Add Camera::State::Armed, remove obsolete Readout

* Replace auto_ptr by unique_ptr
* Add HeapPtr<T>, a unique_ptr with a Deleter set to ::free

* Create Stream::ImageData from MessageNData and include comp_type
* Add some optimizations

* Allow executing a CurlLoop::FutureRequest::Callback in separate thread
  and improve error diagnostics

* Rename Acq Callback/Finished to Trigger

* Idem for MessagePtr = shared_ptr<Stream::Message>

* initialize triggers _synchronize (previous initializeController),
* Improve error diagnostics by printing request URL
* Create MultiParamRequest dealing with parallel/sequencial requests
* Export initialize, cam_status and plugin_status to Tango
* Replace Initialis[e|ing] by Initializ[e|ing]

* Implemented in detector-integration-20.1.6.45653-ge2626bbef-stable

* https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#f48-dont-return-stdmovelocal

* EXPOSURE, FRAME_TIME, NIMAGES, NTRIGGER, TRIGGER_MODE

Prepare 1.9

See merge request !5