Update for new strax version

Created by: JelleAalbers

This updates straxen for the upcoming strax v0.9.0 release. This will be the biggest strax change since strax was born. Details are in https://github.com/AxFoundation/strax/pull/235.

For straxen, the changes are:

• Add a refresh_raw_records script to convert existing raw_records data to the new format. All other data has to be reprocessed from raw_records. The raw_records hash does not change.
• Update the DAQReader to:
  • Output strax.Chunks instead of raw numpy arrays. This requires the new settings daq_chunk_duration and daq_overlap_chunk_duration to be passed.
  • Create artificial deadtime, indicated by signals in the non-existent channel 799, when the data is too dense to break it over chunks. This was always envisaged but never implemented: now that chunk starts/stops must be specified, the old kludge of just letting data hang over the chunk breaks if needed (and silently corrupting the results) would not work anymore.
  • No longer baseline and fliip the data. This is done in PulseProcessing, so raw_records really is just the raw output of the digitizers (with baselines around 16000 and signals pointing down)
• Update the PulseProcessing plugin to do baselining, flipping and integration of records. The artificial deadtime markers in channel 799 are not yet processed.
• Update the other plugins to
  • Add time and endtime fields to all data types. These are mandatory from now on.
  • Remove some hacks to compensate for the sloppy empty-data handling of the previous strax versions.

I tested this by:

• Converting our favorite 1-minute run 180215_1029 with refresh_raw_records
• Running the fake_daq with this as input
• Processing this to event_info (with and without multiprocessing)
• Verifying that the result still has nice-looking events with plot_waveform

The pax conversion plugin has not yet been updated.