1.4.0

Added

• vector: NEVec::reverse, mysteriously missing until this point.
• vector: Support for rand::seq::SliceRandom, exposing a shuffle function for NEVec.
• set: NEBTreeSet and its macro nebts!.
• map: NEBTreeMap and its macro nebtm!.
• index: NEIndexSet and its macro neis!.

Changed

• index: The ne_indexmap macro has a shorter alias neim and the original has
  been hidden from the docs.