js: adds javascript for glossary page scan

* adds zGlossary library with modifications
UI: adds coll_title to "ATLAS Higgs Challenge"
UI: glossary - adds WIP tags

* adds WIP ‘status’ tags, so unfinished terms won’t show up on the
glossary page
* (addresses #215)
UI: adds functionality for glossary page scan

* creates necessary glossary blocks
* adds glossary term search on ‘main_content’ of pages
* creates a minified version of glossary.json to use as dictionary
* (addresses #215)
UI: adds 'no-glossary' class in page sections

* adds 'no-glossary' class in page sections we don’t won’t to be scanned
* (addresses #215)
UI: changes wording in T&C

* (addresses #715)
UI: adds "external link" icon on external links

* adds “external link” icons on the beggining and end of a link