Moved UWBIR radio related files (unchanged) from MiXiM to INET.
Replaced PhyLayerUWBIR with UWBIRRadio.
Replaced airframe_ptr_t with DetailedRadioFrame*.
Replaced MIXIM_API with INET_API.
Replaced LAddress::L3Type with Address and LAddress::L2Type with MACAddress.
Replaced Signal with DetailedRadioSignal.
Replaced #includes in UWBIR related files.
Ported radio modes for UWBIR radio.
Small compilation fixes for UWBIR related classes.
Ported UWBIR related modules and classes from MiXiM to INET.

Ported parameters and some radio related functions from MiXiM's UWBIRMac to UWBIRRadio.
Added UWBIR radio to nic examples.