One note about the interface - the rotation arrows are very confusing. You should always put the curve on top, rather than on bottom, since most people think of rotation directions based on the movement of a point on the top of the arc. Additionally, the left arrow rotates right, while the right arrow rotates left.
I reversed the order of the arrows, but I'm not sure about flipping the glyphs. Those are the standard unicode glyphs for rotation arrows, I didn't want to use any images on the page. I suppose I could use CSS to invert them.
