Implemented first part of #17: A HierarchyModifier can now be specified instead of the eliminateHierarchy boolean flag. No new functionality is yet added.

Exception handling

- reformatted source code

- added more comments
- need to catch exception by reference, else the message seems to be lost
- test if the message is correct
- test if device is really closed and opened again
- changed names of status variables in control system to match the general naming conventions

enclose CMAKE_BUILD_TYPE in quotes; this transforms it into an wmpty
string and the string command wont complain that its missing an argument
when CMAKE_BUILD_TYPE is not set.

connect the deviceError module with the control system - otherwise it crashes due to an unconnected variable

- use latest backend factory interface and the CDD
- changed code formatting

Cmake treats CMAKE_BUILD_TYPE string as case insensitve. Make the check
for enabling coverage reflect this to make usage less restrictive.