G2 should jump automatically to definition instead of disambiguation if only one match exists

Auto-link to definition when no homonym exists (currently all links are to a disambiguation page).

On a <drupal>/g2/entries/<someentry> URL, if "someentry" matches a single entry in the G2 glossary, G2 should directly jump to that page instead of returning a homonym/disambiguation page with just one entry on it.

[request imported from the G2 wiki]