Adding JSON-powered hours

This adds the JSON-powered hours code to the libraries theme.
Specifically:

- hours are stored in JSON format at hours.json in theme root
- js/core.js has two functions (buildHours and findToday) that will
load the JSON when needed and read out that day’s hours for that
location
- content-location.php, page-main-locations.php, and
page-study-spaces.php have had their old hours code removed (with some
exceptions), and replaced by the needed data-location-hours attribute
that is the needle searched for by buildHours()
- I’m also including new builds of js/build/production.js and
js/build/production.min.js, although they can be rebuilt at any point