v0.16.1

Added

• Added HashTable methods related to the raw bucket index (#657)
• Added VacantEntryRef::insert_with_key (#579)

Changed

• Removed specialization for Copy types (#662)
• The get_many_mut family of methods have been renamed to get_disjoint_mut
  to match the standard library. The old names are still present for now, but
  deprecated. (#648)
• Recognize and use over-sized allocations when using custom allocators. (#523)
• Depend on serde_core instead of serde. (#649)
• Optimized collect on rayon parallel iterators. (#652)