Made application render platonic solid object
Restrucfting platonic solid so subclasses define geometry drawn.
Added PI constant
Got line and point rendering working with Cube and wrote code to
define a perspective projection
Removed unused code
Changed size and thickness of point and line rendering
Controls to specify rendering mode now specified - render method has also been moved to Drawable
Fixed bug where triangle modewasn't working
Created a checkbox to control if triangles of the platonic solid are individually coloured or not