Release v0.4

• Package license changed to GPL-3.0 or later
• New verb: read_catalog: read a catalog from web services or from a file
  (FDSN text, QuakeML, or CSV)
• New verb: scan_templates: scan a continuous waveform stream using one
  or more templates. Templates can be from families or from file
• New verb: print_families: print families to screen
• New verb: plot_slip: plot cumulative slip for one or more families
• New config parameter: clustering_algorithm to select the algorithm
  for building event families. Currently supported options are shared and
  UPGMA (default: shared)
• family_numbers argument is no more mandatory (default: all)
  • argument added to map_families and plot_timespans
• Config parameter trace_average_from_normalized_traces renamed to
  normalize_traces_before_averaging
• plot_timespans: possibility to sort by family_number
• New options for map_families to select a map style and a zoom level for the
  map tiles
• New option --minevents (-m) for many verbs, to select families with a
  minimum number of events
• Support for events with no location
• Bugfix: plot_timespans: correctly plot x time axis when sort by time