Contains different movement models and
related classes for the simulator. All movement models have to be in
this package and must extend the {@link movement.MovementModel} class
so they can be dynamically loaded to the simulator. The classes to load
can be specified trough {@link core.Settings} class' settings source.
See MovementModel class and classes extending it for details about the
settings. Complex movement models can store their other classes (the
ones that don't extend MovementModel class) to sub packages.