Fix solution output

Signed-off-by: Jan Losinski <losinski@wh2.tu-dresden.de>
Simplify seen_table update path

Signed-off-by: Jan Losinski <losinski@wh2.tu-dresden.de>
Improve Round_data and Iteration_data

We do not need copy-constructed fersions of them.

Signed-off-by: Jan Losinski <losinski@wh2.tu-dresden.de>