Cuboid: does not inherit from Prism.
Shape: renamed Shape to Shape3D since it represents a 3D shape.
Polygon: Polygon is not a 3D shape.
Shape3D: is not a cObject.
PhysicalEnvironment: factored struct Box out.
Geometry: functions start with the prefix calculate were replaced with the prefix compute to follow the INET terminology.
RadioMedium: constraintAreas should be NIL when there are no radios to compute the constraintArea.
NeighborCacheTests: gave better names.
IVisitor: moved to src/common from src/common/geometry.
Geometry, Cache: fixed some headerguards.