Added OBJ object loader

Added a parser for Blender OBJ objects, allowing importation of more complex objects into the project. The objloader class, inspired by Tutorial 7 on the opengl-tutorial.org website, can parse basic Blender objects and extract vertex, normal, and UV coordinates for use within this project.

Note that as-of this commit, only the parser has been created: the class still cannot be used to load OBJ objects onto the scene.