Omedit creates wrong pathnames when objects are moved

[massimo ceraolo]

This thicket is different, but related to #3608
It regards the fact that when dragging components from a package, OMEdit generates wrong pathnames.

Steps to reproduce:
1) load and open Rpkg.mo
2) open model ER. Check it -> ok
3) drag SimpleR on the model. The following correct code is generated:

SimpleR simpleR1 ;

4) move simpleR1 using mouse or keyboard. The code is changed into:

Rpkg.SimpleR simpleR1;

This code is wrong and generates an error message when checking the component.

Note that at step 4) the simpleR1 icon is displayed, even though the component should be not visible (and is not visible to OMC, indeed), because of #3608.