Add Graph class with basic methods and documentation
Merge branch 'dev' into feature-csp
Minor change with groups of methods in Graph.hpp
Merge branch 'dev' into feature-csp
Base CSP data structures and beginning of CSP init
CSP global domain creation with colors consistency
CSP group slots domains creation
Rename group domain gen. to slots domain gen.

and following changes.
Basic version of plan generation from domains
Merge branch 'feature-csp' into dev