playground executable for experimenting with solvers and preconditioners

See merge request !410

Create sparse matrix with contiguous memory for MatrixMarket.

See merge request !481

Use dune_add_test properly

See merge request !475

[amg] fix w-cycle

See merge request !474

The current behavior (allocating each row separately ) is rather
surprising and unnecessary as the matrix market file stores the
number of nonzeros anyway. Hence we now pass this number to
BCRSMatrix::SetSize to get the most efficient behavior

Const correctness in iterative solvers

See merge request !421

[cleanup][cmake] Remove CMAKE_METADATA_FILE.

See merge request !479

Remove unused-parameter warnings

See merge request !472

Add inline to splitFilename

See merge request !477

Fix inconsistency in matrixmarket file IO

See merge request !465

[bugfix] value name for creating amg criterions from parametertree preSteps->postSteps

See merge request !473

[SIMD] fix Solvers - if one lane has zero initial residual

See merge request !469

add missing include in foreach.hh

See merge request !470

If one lane has zero residual (e.g. the RHS and initial guess is zero) the division
in the factor for the minimizing and orthogonalization is handled explicitly to
avoid NaNs.

spqr solver with block matrix

See merge request !409

add test for block size test for spqr

deactivate std::complex tests of spqr

Remove deprecated code

See merge request !467

CHANGELOG.MD: Be more precise about FieldTraits requirement in ISTL vector types

See merge request !466

See discussion at core/dune-istl!460