remove commented part of ExceptionHandlingDecorator - 'void doPreRead() override' and its implementation

removed doPreRead() / doPreWrite() , doPostRead() / doPostWrite() from ExceptionHandlingDecorator - tests are now failing

  - Cleaned up comments
  - Place using-declaration of buffer_2D to class definition so the base
    class name can be omitted in the implementation

- remove "void ExceptionHandlingDecorator::setDataValidity(DataValidity newValidity)"
- add "void ExceptionHandlingDecorator::setOwner(EntityOwner* owner)" and remove owner setting in constructor

  - Cleanup:

    - Reorder code in Application::createDeviceVariable
    - Separated ExceptionHandlingDecorator constructors for writable and
      non-writable registers
    - cleaned up doPreWrite

- New flag parameter for ExceptionHandlingDecorator::genericTransfer.
  Method does not invalidate data if flag invalidateOnFailure is set to
  false.
- Write related methods in ExceptionHandlingDecorator set
  invalidateOnFailure flag to false

Changes resolve ticket #57.

  - First compiling version, tests pass, hope it works...
  - Needs some tweaking

- 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.

Fixes #39

  DeviceModule and ControlSystemModule now do not take the optional prefix argument in their constructors any more. Use the [] operator instead to get the submodule.

- Add ExceptionHandlingDecorator and decorate all device variables with it.