Fix car_index bug

[schakalakka]

There is a bug regarding the car_index in the resulting trip_table after a tapas run. Only the first car in a household is used even it is already book by another household member,

[schakalakka]

a first fix for the car_index bug

now the second car of a household will be used.

See commit 7a18a6e in branch fix_car_index_bug_second_attempt.

There are still some issues:

1. Sometimes members use a car which is already booked at that time (see TPS_Worker.java line 129)
2. Is the car wrongfully assigned to several households? No handling in this case so far.
3. There are basically two cases: One for Household Member-sorting COST_OPTIMUM and one for the rest. It is also not clear why the second case works at all.
4. Sometimes there are a set of plans for a person and ALL of them are infeasible. Why? And why are infeasible plans not dismissed immediately anyway?

So far it is not merged with master but it will be eventually. It is needed for the TAPAS-CURRENT interface.