Rearranged processing of fanouts and their consuming nodes. A list of
consuming nodes and implementations is passed to the fanout constructors,
so the nodes don't have to added later. This resolves conflicts in the
order in which accessors are decorated and added to the fanouts.

FanOut constructors could still use refactoring.

Ongoing refactoring. Consuming fanout works again.

- Exception handling decorator and ThreadedFanOut send condition variable notificatios via the DeviceModule
- FanOut sends terminate to impl and all slaves.
Solves (some?) shutdown issues, but breaks bi-directional array test.

- implement ThreadedFanOut version with return channel
- add test for ThreadedFanOut with return channel

- add all networks triggered from the same node to the same TriggerFanOut
- put all feeding nodes in a TriggerFanOut into the same TransferGroup

- added some class documentation

- some more code cleaning

changed the internal thread implementation to boost::thread and make use of the interruption points to properly terminate the application

- fixed copying only the first element in some situations

partial fix for problems due to moving to new ControlSystemAdapter structure: allocate and use the buffer from the NDRegisterAccessor
tests still do not pass

Adapation to the unified versions of ControlSystemAdapter and DeviceAccess.

Status: Library compiles, tests do not yet compile.

- extended the trigger tests
- removed some debug output

Use the threaded version of the FanOut if a pushing feeder is distributed to multiple consumers, so all consumers receive updates immediately.

- 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()

start the synchronisation thread of the FanOut to "convert" a poll-type feeder into a pushing feeder by putting in an external trigger.

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.

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