Comment 17 for bug 481506

@Eduard, adding the control point for spirals and rectangles is easy, I'll post a patch after I figure out some details about my bzr workflow (namely, do merge-directives created with "bzr send" preserve the full commit message? And how are they applied?).

About adding the visual indicator for the center of the bounding box of selections, I think some minor refactoring to the current code is needed.

Right now, in src/seltrans.{h,cpp} the name SP_ANCHOR_CENTER is used to refer to the _rotation_ center, the one shown when the selection is in STATE_ROTATE.

What I am going to add is a control point for the center of the selection in STATE_SCALE.

So my doubt is: can I rename the current SP_ANCHOR_CENTER to something like SP_ANCHOR_ROTATION_CENTER? And then use SP_ANCHOR_CENTER for the bounding box center?

Thanks,
   Antonio