Accesses for pure local content

[mandelsoft]

The idea of having accesses not only for externally referenceable content able to be added as access methods to a CV
is very good.

The problem hereby is that those accesses cannot really provide a serializable access method specification.
In some providers a localBlob access method is faked. But this could never directly be added to
a CV stored in an OCM repository.

When writing a Component(version) to a repository containing such accesses they must be mapped to repository
specific instance of the access. As described in #2, so far, this is always done, regardless of the access type.

May be, instead of faking local access methods, we could use a dedicated access explicitly stating that
it describes a non-serializable access.