add builder for creating specific IRIs.
add route for versioned iris

In versioned iris the normal iri route is prefixed
by a ref/:version_number in order to fetch the state of
a specific version of that ontology-(member).
change find_with_iri to perform like query

This should allow iri-finding with ignoring the
hostname-schema prefix. It is not perfect, but it'll
work until we've change the iri-storing system.
allow versioned-file-download via ontologies.
use versioned_iri for hets instead of iri

In order to be capable to process multiple commits
of the same ontology at once, we'll need to use the
versioned iri.
force invoker to port 3000

This is to circumvent development problems
with the hets-api.
allow to hets-stub specific ontology-version.
fix failing test with versioned-hets stubbing

Also fix problems regarding the mass-commiting (for each it-block) into
the factory-repository at least in this spec. We need to find a more
general solution.