Correctly save diagram resource after setting the link with a Network
Fix modifiers for InstancePattern constants
Startup: initialize instances when network is empty
Startup: initialize network ports when network is empty
Fix bug in business model with connections

If a connection is made by user in the wrong way, the resulting
net.sf.orcc.df.Connection object has now the right src & trgt attributes
Startup: initialize connections when Network is empty
Fix Connection creation

When a connection join something with a Network port, it must be defined
with the port as Vertex and null as port.
Minor fixes on generic Update feature
Basic initialisation of a Diagram from a Network
Display instances name and refinment when adding
Display port name when adding it to the Diagram
No more in/out attributes on ports
Complete diagram generation from network

Now, it must be automatically layouted