Moved objects

OpenGL/Objects now only contains wrappers of OpenGL objects, all higher-level objects are moved to OpenGL/HiLevelObjects. Also moved LocationMappings to OpenGL/Data.
OpenGL/Objects.hh still includes the high-level stuff. In the hi-level collection multiple alternative concepts can be collected to achieve similar functionality (Uniform objects instead of UniformBuffers for example) which is fine but should not lead to confusion that just the OpenGL objects in Objects/ are the main building blocks on which the HiLevelObjects/ rely on.