Refactor scene loading
- Move "Scene loadFromJson(..)" to sceneloader.
- Add util/factory2.d module for more generic instatiation of objects.
- Move from SceneLoadContext to Scene the AAs of type string : scene element.
- Remove the member "string name" from Geometry, Light, Node, Shader and Texture
- Add new exception type for scene elements of the same category with the same name.
- Refactor util/prod.d so it does not require importing modules at place of mixin instantiation and templates for generating many fields as T, T[] or T[string] at once [currently unused].
- Slight improvement to .gitignore
- Add build configurations to dub.json. From now on binaries will be produced in the bin/[platform]/ folder.
Merge branch 'master' of https://github.com/ZombineDev/Chess2RT.git