moved files into new structure

dune/stuff/common/color.hh

dune/stuff/common/debug.hh

dune/stuff/common/filesystem.hh

dune/stuff/common/header/disable_warnings.hh

dune/stuff/common/logging.hh

dune/stuff/common/math.hh

dune/stuff/common/matrix.hh

dune/stuff/common/mem_debug.hh

dune/stuff/common/misc.hh

dune/stuff/common/parameter/configcontainer.hh

dune/stuff/common/parameter/validation.hh

dune/stuff/common/printing.hh

dune/stuff/common/profiler.hh

dune/stuff/common/signals.hh

dune/stuff/common/tuple.hh

dune/stuff/fem/localmassmatrix.hh

dune/stuff/test/common_color.cc