ontohub/ontohub — pull request #487 by 0robustus1 (2013-12-10 16:29:15+00:00)
Title: fix to_s of Links to use new iri-syntax

IRI has '?' as delimiter now, and not '#'.
Also we should never return nil in to_s, since
link_to will fail with the gsub error.

Should fix #480.