adding --paint only option for all a) b) and c)

[jafranc]

This PR introduces few fixes and improvement to 'extrude_and_rotate.py', as follows :

• Fix the non-anisotropic permeability tensors in spe11-b
• Adding a '--paint' option that only paint properties on 2D meshes for spe11-a and spe11-b.
  As for spe11-c, the generated mesh is already 3D, '--paint' is the only valid option.
• Adding the --poromult porevolume accessed pore-volume multipliers acting on a VOLUME celldata array rather than on the PORO celldata array that contains porosity. It avoids crash of formula splitting fluid phase from solid using weighting of the form (1-PORO[i]) and PORO[i]

Note: for spe11-c, this only paint inherited permeability tensors from spe11-b and not the rotated version obtained from Eq. (4.4), as it can be introduced or obtained as a post-processing of the read values

Note: in the case of painted 2D meshes, the gmsh generated vtk meshes introduces VTKLINE elements that count as cells. On these cells, the permeability, porosity and attribute (region tag) are set to -1.

[berndflemisch]

This is still marked as a draft. What's the current status?

[jafranc]

This is still marked as a draft. What's the current status?

I think it is ready for review