Added Color data to each point of a polygon.
Added some default values to Color alpha.
Fixed some include guards.
Small change to Polygon::Point.
Changed the default color to white.
Added a non-const iterator type to Polygon and made Polygon::Points public.
Big Renderer interface change.  Removed Rectangle and Circle methods and added a Polygon method. Added DeleteBatch method, and introduced the concept of a Batch.  Also added thread safety methods.
Added Boost, OpenGL, and GLEW to the dependencies.  Added build/ folder to contain things like the CMake module for finding GLEW (taken from Blender).  Qt is a temporary dependency for testing.
Added a Renderer implementation using OpenGL in OpenGLRenderer.  Added a TestWindow using Qt.  Update CMake file to build the test.