Please implement fast circle/ellipse and rectangle drawing

[kimslawson]

Having something like CIRCLE x,y,r1[,r2] taking a radius to draw a circle, as well as an optional second radius to draw an ellipse, and RECTANGLE x1,y1,x2,y2 would be immensely helpful helper functions, both for speed and code complexity reasons. Cirlcles and rectangles are extremely common graphic elements.

I know that you're trying to keep the size of FB down, and not throw every helper in like a library, but coming from TBXL it's painful to not have these built in.