Add Current status for z3solver.

.../src/main/python_magicstack_immutable/btypes/BRelation.py

...tives/src/main/python_magicstack_immutable/btypes/BSet.py

...itives/src/main/python_magicstack_immutable/btypes/BZ3.py

constraint_solver.adoc

.../hhu/stups/codegenerator/generators/MachineGenerator.java

...hhu/stups/codegenerator/generators/OperatorGenerator.java

...erators/iteration/ConstraintSolverPredicateGenerator.java

...tor/generators/iteration/IterationConstructGenerator.java

...rator/generators/iteration/SetComprehensionGenerator.java

...ups/codegenerator/handlers/IterationConstructHandler.java

...n/resources/de/hhu/stups/codegenerator/PythonTemplate.stg