model rather than create a new version.  Also Junit'ed the updated code.

values.  CpModelTool for extracting version id and incrementing that.

CP_generator will now always create an empty solution and Milp_solver
always expect a solution (even if it empty).

related JUnits, and the main metasolver call to Mapper.  Also tidied up
POM to remove those features/jars that we can get via inheritance,
transitive dependencies and those that are duplicate dependencies.

Missing space between model name and timestamp in command line for milp. Moreover milp is not ready to accept a additionnal parameter