pmModelGroup.[ch] updates

[eugene]

I extended the pmModelGroup functions to allow dynamic manipulation of the
availble models. This lets user code add models without modifying the psModule
installed library. To do this I've added the following functions to
pmModelGroup.[ch]:

static void ModelGroupFree (pmModelGroup *modelGroup);
pmModelGroup *pmModelGroupAlloc (int nModels);
void pmModelGroupInit (void);
void pmModelGroupAdd (pmModelGroup *model);

changed models to defaultModels, and added a new dymically allocated local
static variable *models.

this update is available in eam_rel9_b0

[robert.desonia@…]

merged your branch into CVS main for src/objects directory.