Merge branch 'feature/tiny-matrix-goes-rectangle' into 'develop'

src/algebra/DenseMatrix.hpp

src/algebra/TinyMatrix.hpp

src/output/OutputNamedItemValueSet.hpp

src/output/VTKWriter.cpp

src/output/VTKWriter.hpp

src/output/WriterBase.cpp

src/utils/PugsTraits.hpp

tests/test_ASTNodeFunctionExpressionBuilder.cpp

tests/test_ASTNodeListAffectationExpressionBuilder.cpp

tests/test_AffectationToTupleProcessor.cpp

tests/test_ArrayUtils.cpp

tests/test_DiscreteFunctionP0.cpp

tests/test_TinyMatrix.cpp