Create full (shallow) copy of this storage.
ILArray as new (physical) representation of this storages data.
The ILArray object returned will be of the same size than this object.
Keep in mind, no reference counters are altered! The new object is just a plain
copy of the old one which remains unchanged. Also: "copy" means, the m_data array
will be copied, but (of course) not (!) the objects referenced by the array elements!
Therefore this is a 'shallow' copy only! This is necessary, since objects stored inside
ILArray do not have any restrictions. (Especially they do not have to support the IClonable()
interface.)