Restructured VLBI code, calculate std dev and added options

psrdada_cpp/effelsberg/edd/CMakeLists.txt

psrdada_cpp/effelsberg/edd/GatedSpectrometer.cuh

psrdada_cpp/effelsberg/edd/Packer.cuh

psrdada_cpp/effelsberg/edd/Tools.cuh

psrdada_cpp/effelsberg/edd/VLBI.cuh

psrdada_cpp/effelsberg/edd/detail/GatedSpectrometer.cu

psrdada_cpp/effelsberg/edd/detail/VLBI.cu

psrdada_cpp/effelsberg/edd/src/Tools.cu

psrdada_cpp/effelsberg/edd/src/VLBI.cu

psrdada_cpp/effelsberg/edd/src/VLBI_cli.cu