Implemented link state without acks

In addition, made the following modifications:

- removed commented out cruft and unused code
- improved logging
- const qualified and made public members of events
- deleted link alert events since they are subsumed by link state updates
- removed no unique id entity constructors
- removed unencessary overload of std::hash
- only fire error when rqeuired args are missing if help is not specified
- changed initialization order of objects with program-long life times in around in sim.cc