COB-20: Ported COBALT2 patches back to trunk

.gitattributes

CMake/LofarPackageList.cmake

CMake/variants/GNUCXX11_2018.cmake

CMake/variants/variants.cbm200

CMake/variants/variants.cbm201

CMake/variants/variants.cbm202

CMake/variants/variants.cbm203

CMake/variants/variants.cbm204

CMake/variants/variants.cbm205

CMake/variants/variants.cbm206

CMake/variants/variants.cbm207

CMake/variants/variants.cbm208

CMake/variants/variants.cbm209

CMake/variants/variants.cbm210

CMake/variants/variants.cbm211

CMake/variants/variants.cbm212

CMake/variants/variants.cbm213

CMake/variants/variants.cbm299

CMake/variants/variants.cbt001

CMake/variants/variants.dop256