Implementation of Austria Hungary Border Reopened

There are 2 variables associated with AHBC

1. game.persistent_events['austria_hungary_border_reopened']
    This checks if the event is in play

2. game.austria_hungary_border_reopened_tracker
    This is used to track the criteria for the benefit.
    In add influence, it checks that all spaces influence is placed are in East Germany
    In SC, it is true if the player confirms use of AHBC during the states.austria_hungary_border_reopened_check