* Added 3D multi-frame readImages cmd and events on image counters & data
* Changed DATA_ARRAY header definition (version 2):
  + Max number of dimensions is reduced to 6
  + DimStep is now a 32-bit arr. with the dimension strides in bytes:
  + By default DimStep[0] is the size of the data
  + The total header length is unchanged, v2 is backward compatible if
    NbDim <= 6 and DimStep is not used.
* Limit the event push rate to a maximum value, configurable
  by the image_events_max_rate attribute (default 25/s)
* Renamed last_image_pushes_events attr. to image_events_push_data.
* Removed blocking imageStatusChanged calls in prepareAcq and last acq frame
  ready, creating Tango dead-locks
* Added test_frelon_spectroscopy_lima_tango.py:
  + Precise readout time measurement of the different HW RoI modes
    and comparation with the theoritical value reported by the camera
  + Configure the Kinetics RoI mode for fast Spectroscopy measurements
  + Stripe concatenation readout using 3D data from readImageSeq