Radio: Added preliminary obstacle support.
Radio: Revived communication/interference range display.
Radio: Removed obsolete radioMedium.alpha and fixed renamed parameters.
Moved NaN macros to FWMath.h
Radio: Added obstacle loss to the medium.
Radio: Added cuboid to geometry.
Environment: Added space min and max to physical environment.
Environment: Added a few other materials.
Environment: Added NED file for PhysicalEnvironment.
Radio: Added leaveCommunicationTrail parameter.

Renamed other parameter to recordCommunicationLog.
Geometry: Fixed intersection computation.

Also fixed virtual function overrides.
Radio: Fixed tests before adding obstacle loss to radio medium.
Radio: Added ObstacleLoss to RadioMedium.
Radio: Removed unused constructors and some cosmetics.
Radio: Added max speed to mobility interface and the radio medium.
Radio: Added XML format for physical objects.
Radio: Added inet namespace to new files after merge.