UTC Calendar, Update moment/bootstrap-datepicker

Use the :clock value to parse the datestring in the view before invoking
javascript. Native UTC handling in datepicker may be coming in v4.0
(eta - eventually). For now, formatting it before introducing the
javascript works.

Update moment.js and bootstrap-datepicker, while we're at it, because
why not.

Fixes #81
Merge branch 'calendar_utc' of github.com:anchor/machiavelli into calendar_utc