add create_version method
add create_ontology method

Conflicts:
	app/models/repository/git_repositories.rb
remove iri argument
simplify ontology retrieval
make user argument mandatory
rename variable
add do_not_parse to save_file
fix version having wrong path bug
move tests to rspec
further simplification
begining improve the rake task for categories
rake task loads ontology from ontohub.org

if it loads nessecery and imports it into the meta
 repository. and it generates the categories
remove non needed variable and method call
Add SaveOptions to reduce arguments of save_ontology
reintroduce ontology-parsing transaction

Seems during the move to the new parsing system
we forgot to also use a main transaction again.
fill child-version with all necessary parent info

The versions of child-ontology should contain
the same data as the corresponding parent version.
This especially includes the commit-oid.
add parent to ontology-version

Also set the parent accordingly during parsing.
prevent child-ontology-versions from being pending

Currently child-ontology-versions are always pending.
As we will now actually display them, they should
be marked as done. Especially since child-ontology-versions
can only not-exist or be done.
show child-versions for child-ontologies

Instead of referring to the parent (and actually
displaying a 'wrong' version), we should
use the child-versions themselves.
prevent ontology-state update for child-versions.