* Add initial Ellipse Tool to the Editor Mode. Currently there's
something wrong with the algorithm and the ellipses have a sort of
'lemon shape' to them.
* Refactor the IterLine/IterLine2 functions to be more consistent.
IterLine used to be the raw algorithm that took a bunch of coordinate
numbers and IterLine2 took two render.Point's and was the main one
used throughout the app. Now, IterLine takes the two Points and the
raw algorithm function removed.