fixed another uncought exception when converting e.g. an Inf from double to float (was still occurring for D_spectrum)

Temporary roll-back to the periodic update polling instead of the readAny()-based update logic. This is necessary, since the readAny() implementation seems to be too slow for bigger servers like the LLRF server. A proper solution should be found to improve the performance of readAny() for larger number of variables.

adding the current path to the linker flags before the other link pathes so an installed library is not taken, but the one supposed to be tested

- improved test printout (manual checking of exception messages)

fixed problems with the rpath: rpath on installed library was not set; tests were using installed DoocsAdapter instead of library from build directory

- set required version for the ControlSystemAdapter

Added CMakeLists.txt + support files to allow building the project via cmake. The cmake files used by other project to find this library as a dependency still have to be added.