fixed sending triggers multiple times when the trigger is distributed to multiple targets (TriggerFanOut takes care of the distribution now)

made the instance of the Application::testableMode_mutex static, since otherwise the unique_locks returned are no longer valid in any but the first instance of the application (which affects tests)

fixed race condition in testable mode: now stepApplication() will use a semaphore counter to ensure that all processing is done

Added a TestDecoratorRegisterAccessor which is optionally put around accessors to facilitate test of applications. This TestDecoratorRegisterAccessor does not yet do anything, functionality will be added in the next commits.

Rebased the ScalarAccessor and ArrayAccessor classes onto the mtca4u::NDRegisterAccessorBridge class.
Known problems present: code compiles but tests do not run

Changed the FeedingFanOut so that it does not extract the meta-data (name, shape etc.) from the first slave but expects it in the constructor. This is necessary since the meta-data is already given by the application.

fixed variable networks with external trigger not being put into the same TriggerFanOut (which is required since they should be in the same TransferGroup)

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

- some more code cleaning

Added names and owners for modules, to build a full hierarchy chain. The syntax for creating modules is now not so nice, a better way has to be found (maybe by adding a macro if better solution can be found).

The readNoNBlocking() to obtain the initial values is now run on all ApplicationModules (incl. VariableGroups) before starting the first module, to ensure the intial values are really processed first.

Read all application inputs once before starting the module threads, so the initial values are correctly present.

For this purpose, additional changes were necessary:
- Added support for constant values as feeders and consumers (just ignore the writes)
- Connect all unconnected application accessors to constants after defining the connections and before creating the implementations
- Renamed the user-overridden function "initialise()" into "defineConnections()", since more actions are now necessary during initialise().
- The connections are now made (i.e. the implementations are created) during the initialisation phase

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

Introduced the DeviceModule class which provides an interface to obtain VariableNetworkNodes for device registers

- performed some code cleaning and refactoring
- store all nodes in a VariableNetwork in a single list, to allow deciding later if a node is feeding or consuming

This commit is an intermediate commit and has known bugs. Almost all tests are failing and the demoApp is not running. Debugging will be done in a next step.

introduced an operator>> and operator<< syntax to connect network nodes. to realise this, the VariableNetworkNode class has been changed into a pimpl pattern.