Doing this disables the implicit copy assignment operator (among others)
which would cause hovac if used on the classes as it would just copy the
pointer, not the data the d-pointer points to. For most of the classes
we don't need a copy assignment operator anyway and in many classes it
was broken before as many contain a pointer of some sort.
Only for our Cacheset Container interfaces we define an explicit copy
assignment operator which could later be implemented to copy the data
from one d-pointer to the other if we need it.