v0.29.0-dev.0

[Unreleased]

Added

• geary-examples module with some basic engine setup examples

Changed

• Switched to our own small DI library for internal module and for addons
• WorldScoped is now the preferred receiver when writing extension functions. WorldScoped.newScope() can be used to
  register systems, observers, etc... and automatically unregister them when calling close on the returned scope