Add connection point to object with simple key+mouse

[MastrUsr]

It would be nice to easily add connection points without opening the edit dialog, which isn't very intuitive.. For example, holding ctrl and clicking with the mouse would add the point.

[nbuhr]

Quickly adding connection points, especially those that snap to grid lines when adding, would be immensely beneficial.

In the current system, connection points snap the side of the X to the grid, rather than the center, and the grid isn't shown by default. It would be more intuitive to show the edits on the shape itself rather than a pop-up dialogue box.