Interaction between buildings and visitors

Visitors and buildings can now interact with each other.

New features:

• Visitors can now be "inside" visitable buildings and interact with them. (for details see #39 (closed))
• Player balance is being continuously kept up to date (income from players and spending per tick and per ride).
• VisitableBuildings can now be inspected. (#32 (closed))

Minor improvements:

• Construction time is now respected by visitors.
• Visitors can exit a building while waiting in the queue but not while on ride.
• Building cost is substracted from player account.
• VisitorEffect is now Serializable and can be modified in Unity.
• Default entry fee can now be set through GameConfig.
• Improved default parameters for restaurant and spendable money.

Bug fixes:

• Visitors now head to the exit if they cannot afford to go on any ride.
• Boolean property change is now added to registeredEvents.

Possible future tasks and improvements:

• Having maintenance cost for each tick may be too frequent.
• Remaining duration could be displayed in seconds.
• Defining an exit position for each building (so visitors are not teleporting when exiting).
• VisitorEffect class may be unnecessary.
• Implementation of construction may be improved in the future (possibly making it more similar to being repaired).