INET requires OMNeT++ 4.3

Reason: we want to use registerSignal() in static context
nb-to-signals: step 1: convert NotificationBoard category constants to simsignal_t
nb-to-signals: remove unused NF_LINK_REFRESH
nb-to-signals: REFACTORING: Use signals instead of NotificationBoard
nb-to-signals: rename method args: category to signalID, details to obj
nb-to-signals: IPv4InterfaceData, IPv6InterfaceData: emit on InterfaceTable instead of MAC module
nb-to-signals: Ieee80211AgentSTA, Ieee80211MgmtSTA: signal sending fixes
nb-to-signals: add @signal declarations for notification signals
nb-to-signals: register signals statically not from initialize()

registerSignal() calls moved from initialize() to static variable declaration
fix MACBase: wrong init stage
RTP: cosmetics
EtherMACBase: error messages improved
EtherLLC: do not refer to msg after having sent it
TCPGenericCliAppBase generalized and renamed to TCPAppBase

The only GenericAppMsg reference in it was in sendPacket(),
the rest of the code can be reused for other kind of TCP apps too.

Conflicts:
	src/applications/tcpapp/TCPAppBase.h
TCPSessionApp: rewritten to use handleMessage() instead of activity()