C-Par rewriting

$C$-**Par** rewriting is a practical necessity for certain modeling applications where we wish to use a rewrite rule to change the value of an outgoing hom for some object *without* deleting+recreating the object.

The intermediate state of the world (and of the rewrite rule, i.e. the $I$ component) in this case would not satisfy the discrete opfibration condition of $C$-**Set**. But this should be functionally equivalent to rewriting where the relevant hom has been replaced by a span.