Goals, beer and toilets

* include/AreaCell.hpp
* src/AreaCell.cpp
Modified inAgent() to handle agents on beer and toilets;

* include/sim_crowd/AgentBase.hpp
Added "goal_" field and virtual methods for handling beer and toilet.

* include/sim_crowd/Agent.hpp
Added methods for handling beer and toilet;

* include/sim_crowd/World.hpp
Added 'beerCount_' field.

* include/sim_crowd/types.hpp
New type (enum) for agent's goals.

* src/CrowdSimulation.cpp
Beer delivery service.

* src/sim_crowd/World.cpp
Formatting fix.
Status printing, performance state, key handling

* include/sim_crowd/World.hpp
Added performance state field 'pstate_' and methods for managing it.

* src/sim_crowd/World.cpp
Printing beer supply and performance state. Methods for managing them.

* include/sim_crowd/types.hpp
New type for performance state.

* src/CrowdSimulation.cpp
Key handling for performance state change.