Clean up include structure in pdelab/backend
The chaotic include structure in the backend
folder has to be cleaned up:
-
Move all ISTL-related includes to backend/istl
-
Deprecate old files moved to backend/istl
-
Add new header backend/istl.hh
that includes all ISTL functionality -
Move all Eigen-related includes to backend/eigen
-
Deprecate old files moved to backend/eigen
-
Adjust backend/eigen.hh
to include all Eigen functionality -
Move tags.hh
to foldercommon
-
Remove PETSc files, they are completely broken and need to be reimplemented from scratch anyway