Implement faster version of circle and ellipse drawing
Capitalize parameter description
Add example to line drawing function
Add example to polygon drawing function
Add example to circle_perimeter drawing function
Add example to ellipse_perimeter drawing function
Add example to ellipse drawing function
Add example to circle drawing function
Add example to set_color drawing function
Merge pull request #568 from ahojnnes/circle

ENH: Faster version of circle and ellipse drawing.