add problem modeling capabilities
full control over obj-func and insertion heuristic
added problem states
turned fixcostcalc into soft constraint
refined to read config files without static cost calculators
created builder to have full control over objective function and
stateless/-full constraints
tested new methods .get/putProblemState
removed return statement if route is empty

now, visitors run even route is empty, thus visitors need to deal with
empty routes
added javadoc
added constructor for AlgortihmConfig
modified acc to AlgorithmConfig
rename putDefaultProblemState to addDefaultProblemState
removed warning in core.problem.constraint.ConstraintManager.java