v0.12.0

Changes

• New component API
  • Components are no longer classes, just simple string ids
  • Use the component function to create type-safe ids
  • Entity methods have been updated accordingly
• New system api
  • Events are now passed as a second parameter
  • Use the system function to limit a system to a specific event
• New world api
  • add has been renamed to create. It no longer has arguments
  • Outside and async calls have to be wrapped in world.run