namelist parameters

[fjansson]

Some namelist parameters can appear in multiple lists.

thls in SURFACE, PHYSICS
isurf in SURFACE, PHYSICS

This causes trouble at the moment with the OMUSE interface, when starting from an existing case.
If this is changed, all cases should be checked.

Other namelists have parameters with the same name, e.g. dtav appears in many output and sampling lists. This is fine, since these are different parameters.