Code review comment for lp:~widelands-dev/widelands/bug-1811583-desync-with-territorial

I haven't tested it but the code is looking good, thanks.
Regarding the documentation: Please update the documentation of win_condition_functions::broadcast() since it no longer waits for roadbuilding. Also, could you add a comment in coroutines.lua (similar to ui.lua)? In multiplayer, these methods should either not been used or used for all players at the same time.