Seg. fault when reusing the factorization

See merge request !62

Commit 49a1a43e introduced a seg. fault when reusing the factorization in Solver::solve(true) --> remove calls to removePetscData(): it seems to be already handled by MatrixFactory<>::~MatrixFactory()

add FieldInterface<>::numberOfLinkedDofs()

See merge request !61

Added warning when trying to use high order Lagrange elements

See merge request !59

New example: Helmholtz reflection of a plane wave

See merge request !58

Win32: CYGWIN/MSYS flag not set by the Ninja CMake Generator --> check for WIN32 only...

See merge request !57

Vibro-elastic first example

See merge request !56

CYGWIN/MSYS flag not set by the Ninja CMake Generator: checking for WIN32 only seems however sufficient

removeConstraints

See merge request !55

std::aligned_alloc() and ms-windows

See merge request !54

std::aligned_alloc() is not available with ms-windows (at least with msvc and mingw): use _aligned_malloc()/_aligned_free() in that case

call Vector::removePetsc() inside Vector::clear()

See merge request !53

This reverts commit afa4dbfa.

compute eigenvectors in algebra::eigenvalues()

See merge request !52