added preliminary support for tags to application variables which can be searched for and used to generate virtual modules

fixed duplicated triggers when triggering multiple transfers with the same application variable (e.g. as used in tests frequently)

removed the boost libraries from the test since linking against the boost unit test library leads to crashes on newer gcc/boost versions

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

- delete the copying operator=

made the instance of the Application::testableMode_mutex static, since otherwise the unique_locks returned are no longer valid in any but the first instance of the application (which affects tests)

- updated the tests for the testable mode and test the TestFacility class there as well

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

implement the "testable mode" in which the application can be paused and resumed by the test routine

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 replacing Array and ScalarAccessors, which was broken after moving to the NDRegisterAccessorBridge-based accessors

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