add solverfactorytest

src/CMakeLists.txt

src/data-structures/program_state.hh

src/factories/stackedblocksfactory.cc

src/multi-body-problem-2D.cfg

src/multi-body-problem-data/bc.hh

src/obstaclesolver.hh

src/solverfactorytest.cc

src/spatial-solving/fixedpointiterator.cc

src/spatial-solving/solverfactory.cc

src/spatial-solving/solverfactory.hh

src/spatial-solving/tnnmg/functional.hh

src/spatial-solving/tnnmg/linearcorrection.hh

src/spatial-solving/tnnmg/tnnmgstep.hh