cordyceps v0.2.0

Breaking Changes

• Fix use-after-free in List iterators (#203) (1eea1f2)
  This changes the type signature of the list::Iter and list::Cursor
  types.
• Add Drop impl for List (#203) (ea7412a)
  The List::new constructor now requires a T: Linked<list::Links<T>>
  bound.

Added

• Add List::len method (#204) (e286c61)

Fixed

• breaking Fix use-after-free in List iterators (#203) (1eea1f2)
• breaking Add Drop impl for List (#203) (ea7412a, fixes #165)