copyright header adjustments
WHATSNEW and ChangeLogs update /1

- added missing ChangeLogs
- added 'inet-3.x' note to all ChangeLogs
"changes in the inet-3.x branch:"
Changelogs update /2
WHATSNEW: Added geometry, environment, power and physical layer models.
doc: moved changelogs under the src/inet tree
Radio: Added IInterference and Interference classes.
Radio: Changed medium to use the interference class.
Radio: Changed computeReceptionDecision to use the interference class.
Radio: Changed computeIsReceptionAttempted to use the interference class.
Radio: Changed computeListeningDecision to use the interference class.
Radio: Changed computeNoise and computeReceptionIndication to use the interference class.
build: fix to avoid operator << ambigous issue with clang.
build: disabling "hides overloaded function" warning
Graphics: Added tags to figures.
Mobility: Removed debug print.
Radio: Changed obstacle label to use a label figure.
Graphics: Followed recent omnetpp canvas API changes.
Radio: Extended IErrorModel with preliminary layered radio support.
Radio: Added ISNIR and friends.