Added animation, an animated state, an animate-to step property and published postContent property.
* Progress is now tracked and the styles are only updated when they need to be changed.
* A custom amount of steps can be specified for the progress bar.
* spotlight is only disabled while the bar is in-progress.
* Animation is toggled by the presence of the `animated` CSS class.
* Added animation bounce like the example video.

Enyo-DCO-1.1-Signed-off-by: Blake Stephens <blake.stephens@lge.com>