#3 Optimizepoly()

[Neo]

If you add a circle to a polygon or a part of a
circle. there will be one point per angle (degree),
that means 360 entries for one complete circle even if
there are less pixels effectively drawn. That means
low speed and high memory consumption. Idea: create an
optimizepoly function and rewrite the add and insert
functions that way, that they check whether the pixel
is already in the poly or not. If it is, do not add
it. If not, add it.

PS: I've done that manually (I mean, I wrote some
small programs which did that) with the UI of CFMove.
Result: the saved polys where about 2/3 smaller than
the original.