electron-flow arrows and shortcut groups

Hi,





Electron-flow arrows won't begin or end at shortcut groups. They should be able to do. E.g., I should be able to put the head of an electron-flow arrow at an OEt group.





If the shortcut is expanded or ungrouped, the electron-flow arrow should point to the attachment point.





-- Bob

OK, I implemented it. Contracted superatom S-groups can be electron flow arrow end (or start) points. If the group is expanded, then the arrow points to the primary attachment point. You will find this feature in the next 4.1 beta.