Make possible to create Hydrax, SkyX, InputMapper and SoundListener ECs unparented without crashing.
Scene::CreateSceneDesc*: create dummy components unparented. This way f.ex. when user imports txml containing EC_Sky to Tundra, the sky box doesn't appear in the scene until user has accepted the importing.
Entity: register also dynamic property component accessor using 'lowerCamelCase' format in addition to the old 'alllowercase' format in order to enhance usability and readability.
Demonstrate usage of the new lowerCamelCase component dynamic property accessors in the Canvas demo scene.