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.
Radio: Added SNIRBase and changed functions to use ISNIR where appropriate.
Radio: Added dummy error model module and update fingerprints.
Radio: Generalized error model for IEEE 802.11 radio.
Radio: Renamed computeMin to getMin.
Radio: Added error rates to reception indication.
Radio: Fixed running multiple runs in the same simulation.
Radio: Simplified scalar names.
Radio: Moved radioChannelChanged signal to Ieee80211Radio.
Radio: Added error rate signals.
Example: Added example that shows how PER, SNIR, and distance relates to each other.
Radio: Finalized the IEEE 802.11 error model.

The old error model still used dblrand, the new one is purely functional.
Updated fingerprints.
Radio: Renamed variables for easier understanding.