[handbook] Move passage about guidelines and delete .tex file

See merge request !1360

[handbook] Update structure and folder setup

See merge request !1339

[handbook] Add link to DUNE cheatsheet.

See merge request !1343

Fix/relate numcells to refinement

See merge request !1329

[component] Remove defaults from constant component

Closes #579 and #608

See merge request !1315

remove assertion in mpfa local assembler base

See merge request !1336

Cleanup freeflow tests

See merge request !1335

Remove primaryVariableName() from model traits

See merge request !1334

* clean-up includes
* remove faulty usage message
* init gridVars with one argument

* clean-up includes
* remove faulty usage message
* init gridVars with one argument

Melanie Lipp authored 6 years ago and Kilian Weishaupt committed 6 years ago

* use scv.dofIndex() == 0 to determine lowerLeftCell
* use correct number of cells in case of refinement for fluxOverSurface

* used outdated names
* now implemented in IOFields

* used outdated names
* now implemented in IOFields

[cleanup] Fix #613 deprecation warnings from gridvars->init

Closes #613

See merge request !1333

Remove unused function isWall.

See merge request !1328

Fix #579 where is was noted that 1.0 as default is more a disadvantage
than an advantage. Just specify 1.0 in the input file explicitly
instead.

Fix #608

Stokes-darcy coupling with maxwell stefan difusion

See merge request !1020

Feature/velocity output with mpfa

See merge request !1320

[test][2pfracture] use single executable for gravity on/off

See merge request !1323