[X] Define solution space,
that is used by the backtracking optimization.
This could also be used for ConstraintGroupBasedRepair in order to have standardized solution manipulation interface.
-> EnumerableSolutionSpace
[X] Define online optimization for this and make backtracking optimization algorithm.
-> net.splitcells.gel.solution.optimization.OnlineOptimization
[X] Hotfix systematic problems with rating system
regarding equality,
which were found and create ticket
in order to fix the systematic problem. -> #37