fixtures: change description of ATLAS

* Changes description of ATLAS.  (PR #490)
CMS: adds CDATA tags for embedded HTML in fixtures
UI: changes text in "Download" button on records

* ( addresses #443)
collections: fixes error in "collection_overview"
records: updated record-brief with "Global Tag"
templates: propagate recent metadata additions

* ( addresses #480 )
UI: link to collections fixed