Ideas for inhomog chan dens
Making naming of inhomogeneousParameter etc. more uniform, e.g. no inhomogeneousParam

Adding notes/annotation to <segmentGroup>, to facilitate adding nseg
metadata
Removing superfluous example NML2_CellVariableParams.nml (example at
NML2_InhomogeneousParams.nml covers var params)
Merge branch 'test_inhomogeneous' into development

* test_inhomogeneous:
  Making naming of inhomogeneousParameter etc. more uniform, e.g. no inhomogeneousParam
  Ideas for inhomog chan dens