Modeled the Time API in UML
Added new makefile target
Refined the UML diagrams
Started to implement the OMNeTTimer functionality
OMNeTTimer message is now correctly inserted in the FEL
Fixed segaulf problems with the OMNeTTimer.
Received OMNeTPackets are now processed by the OMNeTGates (for PcktAcks).

There is still a bug in the ReliableNetworkInterface class (see FIXME)
The acknowledgment timeout can now be controlled via the omnetpp.ini
The OMNeTClock has now a neat icon and does some logging on EV
Fixed bug with the acknowledgment of braodcasted packets with small workaround

For now only packets are acknowledged as long as they are no ANT
packets.. We might want to change this in the future but it works for
now
Merge branch 'omnetTimer' into develop