can of worms

In the fog of recent discussion it seems that the naming of some of our predicates have become confusing again (or is it just me ... ?) We now have "contains" to point between LDPC and the member Document, as well as various predicates which include 'contain' (previously these were the membershipXX predicates). 

I think I would quite like to return to something like the original membershipXX names, and then have ldp:membershipDocument instead of ldp:contains ...

Roger