ATLAS: update of `atlas-higgs-challenge-2014.xml`

* (addresses #660) (PR #730)
ATLAS: unified FIXMEs in Higgs challenge file

* (see PR #730)

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
UI: adds route for '/glossary'

* (addresses #215)
glossary: updates anchors in json file

* (addresses #215)
UI: adds "Glossary" page

* (addresses #215)
UI: adds link to the "Glossary" from Education

* creates a 4th “action” box in the education section for the glossary