Tieing the corpus fields to the the fields the spreadsheet can display



* Localization infrastruture is ready (need to add the {{contextualize("locale_key")}} into the html files
* more testing for why the new audio recording code isnt being built on travis
* centralized the corpus loading in the spreadsheet app
* tied the fields which the spreadsheet can show, to the fields of the corpus
* TODO make it so the users can re-arange the corpus fields order so that they can have their top-X fields showing in the spreadsheet app, and in the prototpye or any app for consistancy.