made the instance of the Application::testableMode_mutex static, since otherwise the unique_locks returned are no longer valid in any but the first instance of the application (which affects tests)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

fixed poll-type inputs using no longer non-blocking read after the switch to the NDRegisterAccessorBridge-based accessors

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

Fixed a bug that a pointer to a temporary VariableNetworkNode object was sometimes stored (as a trigger receiver or source). Instead now an object with the same data pointer inside is stored.

added function to obtain list of accessors from modules recursively (i.e. including accessors from sub-modules)

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

allow specifying the array length for direct connections between device and control system (as the type is already defined in this case)