add ConfigReader.h to ApplicationCore.h, as the ConfigReader is now more strongly integrated with ApplicationCore

add test for findTag() (was never really tested before), including advanced features like HierarchyModifier::moveToRoot

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.