make Firstround_team_selection::for_host const

Signed-off-by: Jan Losinski <losinski@wh2.tu-dresden.de>
Unittest that firstround order is preserved...

...using the Guest_tuple_generator.

Signed-off-by: Jan Losinski <losinski@wh2.tu-dresden.de>
Integrate firstround selection into algorithm

This splits the first round procesing from the other rounds and use the
Firstround_team_selection for it.

Signed-off-by: Jan Losinski <losinski@wh2.tu-dresden.de>
Remove dummy distances for first round

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