C++ OpenGL Render Improvements

What's New in v2.28

• SpriteRenderer renders a single texture as a sprite
• String::ComponentsSeparatedBy
• Interpolate texture to color shader
• True parent-child matrix math so child objects are rotated/scaled with parent
• Better rendering system: Camera is responsible for renders
• Fixed byte order of Color32 for little endian processors
• Turn on depth test and depth buffer for Z-ordering
• Byte-color support for GLRenderEngine
• Convert SDL_DROPFILE event to UIEvent object