Textures:
=========
Images derived by scaling & editing from:
    Game-icons.net
    https://game-icons.net
    Attribution 3.0 Unported (CC BY 3.0) licence.
    https://creativecommons.org/licenses/by/3.0/

Turtle image derived from
    Mini Turtle 1.13 by neoshard
    Attribution 3.0 Unported (CC BY 3.0) licence.
    alered (current) version
    (c) Nigel Garnett
    Attribution 3.0 Unported (CC BY 3.0) licence.

Code:
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Code created and (c) Nigel Garnett
    Attribution 3.0 Unported (CC BY 3.0) licence.
    https://creativecommons.org/licenses/by/3.0/