Add shapes_basic_shapes example

[RobLoach]

This adds the shapes_basic_shapes example, with some of the associated methods...

DrawLine()
DrawLineV()
DrawCircle()
DrawCircleLines()
DrawPoly()
DrawPolyLines()
DrawPolyLinesEx()
DrawTriangle()
DrawTriangleLines()
DrawRectangleLines()

Avoided implementing DrawRectangleGradientH(), DrawCircleGradient(), as those may require a bit more implementation thought.