internally cross-reference glossary

[kohlhase]

The interaction with the glossary is very unintuitive, we need to internally cross-reference it, i.e. all the term references need to be marked (i.e. shown as defined terms; currently they only turn grey on hover) and they need to carry a link (on left-click) to the corresponding glossary entry.

This is what the user would expect.

Assigning to Akbar for the moment cc: @m-iancu