(*) CLIENT PROGRAM NOT COMPILABLE.

- Added new empty classes: MaterialsSelection and LocalMaterialsSelection.
- Now MaterialsManager inherits from ResourcesManager.
(*) App not compilable at this commit!

- LocalDrawablesSelection class constructor no longer requires a color vector as an argument.
- Fixes have been made in ResourcesManager constructor.
- Added a special constructor to LocalLightsSelection and LocalMaterialsSelection classes for satisfying ResourcesManager class requirements.