some description in  *_van_der_Waals*
added stress_tensor_kind
energy_comparable_type -> energy_comparable_kind

common: assigned right section (section_scf_iteration) to energy_total_T0_per_atom_scf_iteratsection_scf_iterationion
fhi_aims: added more metadata for the parser

## dimension types -> number_of_*

atom_kind_natoms -> number_of_atom_kinds
basis_set_atom_centered_nbasis_functions -> number_of_basis_functions_in_basis_set_atom_centered
basis_set_atom_centered_nkinds -> number_of_kinds_in_basis_set_atom_centered
eigenvalues_eigenvalues_number -> number_of_eigenvalues
eigenvalues_kpoints_number -> number_of_eigenvalues_kpoints
n_k_point_segments -> number_of_k_point_segments
n_k_points_per_segment -> number_of_k_points_per_segment
section_basis_nbasis_functions -> number_of_basis_functions
atom_number -> number_of_atoms

## all meta info names should contain at least one "_"

energy -> energy_value
method -> calculation_method
cell -> simulation_cell

## uniform handling of method related things

stress_tensor
van der Waals
relativity

## other

* links to public wiki
* improved section_method and settings_*

* removed perturbative/scf_converged, now always repeat the section
* added method/method_current to integrate more easily semiempirical and similar
* added explicit section reference type, avoid misusing sections (also
  uses extra key referencedSections)
* added derived key for derived quantities
* redundant would also be supported

breaks parsers, will need fixes

gpaw, lammps, octopus, quantum espresso, sample parser, turbomole, castep, cp2k

skeleton for parser specific meta info: cp2k, castep, gpaw, lammps, octopus, quantum_espresso, turbomole