Proper closing operation
Additional information shown in GUI
Updated docu
Fix for comparisons of string version of address
Handling gates that are not operational when they are registered
Fixed error/logging output
Refactored DownGate handling

Changed significantly due to the recursive interface of the new lower
layers. Moverover, it simplified since the logic moved from the deleted
ProcessDownGate to DirectDownGate, LowerLayerObserver, and
LowerLayerSession.
Fixed order of init and notification to routing service

First switch to operational and than notification to routing service.
Thus, no second notification has to be sent to the routing service.
Fixed disconnect and closing operations
Updated docu
Fixed compiler issue caused by refactoring
Added handling of requirements

Storing and using requirements of bindings within the lower layer is
still missing since the name mapping does not support storage of
requirements.
Fixed issues with newly created gates and connectons
Fixed race condition for EmulatorLayer and Multiplexer

Occurs during loop notifying the observers of a layer in one thread and
another doing event handling.
Corrected docu
Refactored access to state of gates