Independent dynamic highlight functionality

New selection preview (Workspace.ActionMode = SelectVisibleByPickDynamic) is nice, but it cannot be used with custom overlay painting, since there is no way (that i can found) to determine whether SwapBuffers() is already called.

I need to do overlay painting all the time for AutoCAD -like crosshair mouse pointer and other features, so i tried to work-around this limitiation by temporarily chancing the color of the entity under mouse pointer, but that does not work with block references. Also couple of other work-around attempts (including Tempentities and ConvertToCurves) failed for me.

It would help greatly if this SelectVisibleByPickDynamic highlighting could be opened for developer use, in some of the following ways:
- Entity.Highlight -property, which is like Selected -property but different coloring,
- Workspace.Highlight -property containing Entity (or face or edge) which is drawn as in SelectVisibleByPickDynamic, which could be used in different kind of editing situations too, or
- Changing DrawForSelection or other as public method to allow overlay painting of highlighted entty.

Since the actual highlighting funtionality is already present, esposing it to developers should be quite easy to do and it will help us to customise selection on editing functionality that usually is essential part of applications using Eyeshot.