Added an extra level of creation of model factory to support creating
values local to a single model creation.
Added practical usage of model creation in clone factory, where a
restorable model is created once and then used in the returned model
creation. 
Further, changed the clone procedure to map the restorable model against
the new location for the created model before restoring the model. This
is important for commands which have locations relative to the reference
location supplied during their execution.