Resolve "Integrate primary beam functionality I - III"

CMake/FindFFTW3.cmake

CMakeLists.txt

cpp/CMakeLists.txt

cpp/common/CMakeLists.txt

cpp/common/fftresampler.cc

cpp/common/fftresampler.h

cpp/griddedresponse/dishgrid.cc

cpp/griddedresponse/dishgrid.h

cpp/griddedresponse/griddedresponse.cc

cpp/griddedresponse/griddedresponse.h

cpp/griddedresponse/lofargrid.cc

cpp/griddedresponse/lofargrid.h

cpp/test/tlofar.cc

cpp/test/tmwa.cc

cpp/test/tvla.cc

external/README.md

external/aocommon