Offline: Include Semantic UI 'packaged' version 0.16.1.
Offline: Include jQuery 2.1.1 (minified JS + map file).
Offline: Include moment.js version 2.7.0 (minified).

Also remove currently included outdated moment.js (2.0.0).
Offline: Include TableSorter 2.17.2 minified JS and formatter CSS.
Offline: Include Open Sans font from Google Font API.
Offline: Add OFFLINE_MODE config and adjust HTML resources.
Upgrade external resources libraries to current versions.

To align with added offline resources:

* Semantic UI from 0.12.0 to 0.16.1
  (0.18.0 is not yet available on cdnjs.cloudflare.com)
* jQuery TableSorter from 2.13.3 to 2.17.2
* moment.js from 2.5.1 to 2.7.0
Merge pull request #82 from gertvdijk/offlineuse2

Add ability to use Puppetboard offline