CMake with multiple packages and different dependency handling.

experimental/CMakeLists.txt

experimental/cmake/dependencies/blas.cmake

experimental/cmake/dependencies/fftw.cmake

experimental/cmake/dependencies/openmp.cmake

experimental/cmake/export.cmake

experimental/cmake/modules.cmake

experimental/cmake/options.cmake

experimental/examples/CMakeLists.txt

experimental/scalfmm3-coreConfig.cmake.in

experimental/scalfmm3-headersConfig.cmake.in

experimental/scalfmm3-mpiConfig.cmake.in

experimental/tools/CMakeLists.txt

experimental/tools/direct_computation.cpp

experimental/units/CMakeLists.txt