[io][gridcreator] Make construction of tensorgrid more flexible

See merge request !759

* Add a public method taking the positions, cells and the grading
  vectors as arguments.
* The general makeGrid() method now extracts the necessary parameters from
  the input file and calls the new method with them
* The new method can be useful in cases where a tensorgrid should
  be constructed not based on input file data, but on different ones,
  e.g. evalutated by a user specified algorithm

[assembly][analytic] Get source derivative per default from problem

See merge request !757

Feature/improve point source handling

See merge request !755

Feature/use grid singleton less

See merge request !743

[2p2pc] add missing caching definition in CMakeLists.txt

See merge request !758

Feature/small fixes newton

See merge request !756

Feature/2d3d intersection

See merge request !753

Feature/subgrid

See merge request !754

Kilian Weishaupt authored Jan 25, 2018 and Timo Koch committed Jan 25, 2018

* expects a host grid and an element selector
* returns a unique_ptr to the subgrid

[priVarSwitchNewtonController] Make work again with volVar caching on

Closes #432

See merge request !746

Kilian Weishaupt authored Jan 24, 2018 and Timo Koch committed Jan 25, 2018

* fvGeometry, fluxVar and volVar caching
* compare against solution with caching off

Feature/linearsolver multitype matrix

Closes #435

See merge request !744

* Specialize solve depending on whether
  MultiTypeMatrices are accepted by the solver or not

[test] Make backward compatible with dune 2.5

See merge request !750