Build system mods, cxx_tests, NablaYlm.

CMakeLists.txt

cxx_tests/CMakeLists.txt

cxx_tests/build.sh

cxx_tests/cmake/FindFFTW3.cmake

cxx_tests/cmake/FindGSL.cmake

cxx_tests/cmake/FindGTEST.cmake

cxx_tests/cmake/FindMKL.cmake

cxx_tests/cmake/FindSOAP.cmake

cxx_tests/gtest.sh

cxx_tests/src/CMakeLists.txt

cxx_tests/src/gtest_dylm.cpp

cxx_tests/src/test_dylm.cpp

cxx_tests/src/test_dylm.py

cxx_tests/src/test_functions.cpp

cxx_tests/src/test_functions.py

src/soap/CMakeLists.txt

src/soap/SOAPRC.in

src/soap/__init__.py

src/soap/angularbasis.cpp

src/soap/angularbasis.hpp