Expansion of exec_model_free() in preparation for rearrangements in the calc_modelfree module.
This corresponds to one component of the patch_II file attached to https://gna.org/task/?6847 by Michael Bieri (https://gna.org/users/michaelbieri).
Authored by: bugman 2010-01-15
Parent: [r10230]
Child: [r10232]
