Narrowcasting
-------------

This is a simple script for some "narrowcasting" screen.

Certain configuration options can be defined by setting data attributes on HTML
elements. The script will then handle the widgets and slides logic.


Some features:

* Support embedding of data in <iframe>'s and refresh using some timer.
* Support embedding of data in <embed> and update using some timer.
* Support updating parts of the screen data using XMLHttpRequest (AJAX) using
  some timer.
* Date / clock widget, format it with a strftime()-like syntax.
  Supports any locale forthe weekday and month names.
* Support embedded videos, automatically pausing and continueing them when it
  skips to the next slide or looping them.
* A mechanism to poll some file for changes using some timer. When this data
  changes the page is reloaded (forcing also a cache flush). This is useful for
  remotely updating the layouts or scripts.
* Show a newsticker. This uses the JSON Feed format.
  sfeed_json could be used to convert from RSS/Atom to this format. This data
  could be updated using a cronjob.
* Nested/sub-slides in slides, swap out parts of a slide with some duration,
  just like regular screenslides, #slide-ception.
* Progressbar to show the slides remaining duration.
* Hotkeys to skip slides, useful for debugging also.
* Uses vanilla JS with no dependencies on frameworks, etc.
