Release Name: 2.3.0

Notes:
== Rubygame 2.3.0

Release focus: Media resources.

=== Features

- Add: Rubygame::NamedResource mixin module
  - Provides per-class resource repository and on-demand auto-loading behavior.

- Add: Rubygame::Music class.
  - Intended as a full replacement for Rubygame::Mixer::Music.
  - Includes NamedResources mixin.
  - NOTE: Requires SDL_mixer support.

- Add: Rubygame::Sound class.
  - Intended as a full replacement for Rubygame::Mixer::Sample.
  - Includes NamedResources mixin.
  - NOTE: Requires SDL_mixer support.

- Update: Rubygame::Surface class.
  - Includes NamedResources mixin.
  - Add: Surface.load_from_string (NOTE: Requires SDL_image support.)

=== Fixes

- ColorBase had been accidently placed in the top level namespace in Rubygame 2.2.0.
  It is now correctly placed in the Rubygame::Color module.

=== Other Stuff

- Deprecation (will be removed in Rubygame 3.0):
  - Rubygame::Mixer module and methods are deprecated.
  - Rubygame::Mixer::Music class is deprecated.
    Use Rubygame::Music class instead.
  - Rubygame::Mixer::Sample class is deprecated.
    Use Rubygame::Sound class instead.
  - Rubygame::Surface.load_image is deprecated.
    Use Rubygame::Surface.load instead.

- NOTE: Run ruby with -w flag or set $_v = true to enable run-time deprecation warnings.


Changes: