Discovered issues during the usage of the editor and Möbius exportation contraint

- It's possible to link an extended place to an activity directly (this is not correct in SAN formalisms' specifications)
- Input and output arcs don't work in editor (they do in xmi file reflective view)
- Need to introduce some controls about the number of parameters required for the distribution of an activity
- In order to export a model in Möbius format each element must have a unique name