MEDIUM - Attempt to provide a way to navigate between diagrams (Step 1)
MEDIUM - Fixed two issues : 
- NPE when loading VirtualModel resource due to dependency between
resources not yet loaded
- Type of Object to be selected in AddDiagram assignation
LOW - fixed some copyright headers
MEDIUM - Fixing an issue with EMF saving empty models
MEDIUM - moved type maps to ViewPoint, added a VirtualModelInstanceType
for conviviality purpose.
MEDIUM - Working on AddDiagram... STEP 2
Merge branch '1.6.1' of github.com:agilebirds/openflexo into 1.6.1
LOW - Working on AddDiagram, Fixing some NPE
LOW - Removing references to agilebirds in Project Objects URI
LOW - fixing a small NPE issue
LOW - NPE Protection
LOW - fixin a small NPE
LOW - fixing some NPE issues
LOW - removed useless System.out
LOW - removed old source code
LOW - Working on Containment management in EMF - Step 0
LOW - fixing copyright header
MEDIUM - First attempt to deal with EContainers in EMF Models