How Concerns : one class per concern + hierarchy
What Concerns added + How simplified (name useless)
String Templates for the Map
Ajustments
Big commit (yeah that's ugly)
Changing a great part of the MM and resolving compilation issue in the generator.
/!\ it compile, doesn't mean it work  (next commit will)
Line, Column, Pie, and 3 Left work with new meta model.
"ugly" dispatch in the data deserializer code, which is doomed anyway ( "soon" to be JavaScript instead )
Clarify the definition of a Resource : all tuples have to share the visualization concerns applied to their resource.
-> adaptation of the map input and smart campus generator.
Get ride of Pivot, Source & Pair
to use Instances hierarchy (mirror of the MetaClasses)
Will facilitate a generic deserialization