v0.2.1

• Fixes a compiler error.

v0.2.0

• Breaking: Most types now include a ThreadSafety type parameter that controls whether or not it uses thread-safe (Arc, Mutex) or thread-unsafe (Rc, RefCell) primitives.
• This crate is now dual licensed under LGPL v3 and MPL 2.0, opposite to the previous AGPL v3 licensing.