- Remove requirement of an Engine instance in ComponentMapper instances,
as the Engine from the entity passed to get() can be used. Allows for
static initialization of ComponentMappers.
- Store instances of ComponentMapper in a static Map within the
ComponentMapper class itself, rather that inside of Engine.
- Name bit/bits consistently. Some cases of bits were renamed to bit,
such as ComponentType getBits() is now getBit(). Change usage of Mask to
just Bits for consistency.
- Modify access modifiers and field finality where appropriate
- Add comments to public methods in Engine