Make languageOfMaterial multi-valued
Add an endpoint to update the properties of a link
Make Link a temporal entity
Tweak fixture to distinguish link types
Link fixtures were written incorrectly so multiple targets didn't work
Add an additional test access point
Add virtual unit indexing to fabfile
Small tweaks to server runner helper class
Merge branch 'master' into acl_graph
Rework ACL graph setup to fix infinite loop issues and to generally
be simpler. Need to break out some of the ACL manager into a lower
level util layer that deals directly with vertices, rather than the
frames.