tests: statistical: fixed network configurator settings

use IPv4NetworkConfigurator instead FlatNetworkConfigurator
or disable NodeConfigurator in NodeBase
typo
dhcp: optimisation, added TODO
mobility: MoBANCoordinator: added FIXME
ByteArray: bugfix in addDataFromBuffer()
cSocketRTScheduler: bugfix for OmNET 5.0
IPv4InterfaceData: info(): print all multicast groups (do not filter out ALL_HOST_MCAST)
IPv4: added log message
UDPSerializer: parser: parses UDP packet to ByteArrayMessage with payload