Merge branch 'develop' into 'master'

algebra/TinyMatrix.hpp

algebra/TinyVector.hpp

experimental/AcousticSolver.cpp

experimental/AcousticSolver.hpp

experimental/AcousticSolverTest.cpp

experimental/AcousticSolverTest.hpp

experimental/AcousticSolverWithMesh.hpp

experimental/Connectivity1D.hpp

experimental/FiniteVolumesEulerUnknowns.hpp

experimental/Mesh.hpp

experimental/MeshData.hpp

main.cpp

packages/CLI11/.appveyor.yml

packages/CLI11/.ci/build_cmake.sh

packages/CLI11/.ci/build_doxygen.sh

packages/CLI11/.ci/build_lcov.sh

packages/CLI11/.ci/check_tidy.sh

packages/CLI11/.ci/make_and_test.sh

packages/CLI11/.ci/prepare_altern.sh

packages/CLI11/.ci/run_codecov.sh