Release v1.4.0

• Fixed: use strict index hash for caching results
  with audinterface.Process.process_index()
  and audinterface.Feature.process_index().
  Before, the same cache was used for indices
  that only differed in their order,
  and the returned results could be in an incorrect order
  when using the cache.
  This means that caches that were created with an older version
  will not be reused with this version.