add comments + log in teambuilder
remove code dublication

instead of constructing game_classification manualy we now use the
constructor which does this work for us.
I don't know why we didn't do this previously so i didn't delete the old
code yet in case there was a reason for the previous behaviour.
only use convert_ond_saves on old saves.
preserve id= in scenario_generation
remove outdated comment
allow [lua] tags in modifications

which have the same effect as [lua] tags inside [scenario]