No more "orphan" columns
Possible fix for blank node uri generation

Not extensively tested.
Clean up imports
Removed references to columnsCovered

Updated sesamemodelparser so it compiles, but no way to test it.
Merge branch 'rdf_generation_blank_node_fix' into development
Merge branch 'no-orphans' into development
v192: no orphans + Jason's fixes to RDF generation