- fixed a bug in the FanOut which did not wait for the trigger (since ProcessScalar::receive() does not wait)
- fixed a bug in Application::feedDeviceRegisterToControlSystem() not handling the last arugment (trigger) properly
- improved the output produced with VariableNetwork::dump()

added also the consumer-type variables to the XML file

Intermediate commit before the weekend: added options to add an external trigger to a network to handle poll and push properly. Currently it does not work properly.

renamed publishDeviceReadRegister() and publishDeviceWriteRegister() into feedDeviceRegisterToControlSystem() and consumeDeviceRegisterFromControlSystem()

renamed publish() and connectToDevice() into more specific feedToControlSystem()/consumeFromControlSyste() and feedToDevice()/consumeFromDevice()

improved structure of network creation and added a FanOut to distribute values to multiple consumers

Introduced the VariableNetwork describing the connections of variables/accessors before things get actually instantiated. This is needed to generate an XML file containing the published variables based on that information.

This is a first mock implementation with very limited functionality. The idea is based on discussions during the OPC-UA control system adapter kickoff meeting and subsequent personal discussions.