Added ProgressButton
Adjusted the offset of the progress button slider to make it look more natural.

Enyo-DCO-1.1-Signed-off-by: Blake Stephens <blake.stephens@lge.com>
CMB-593: Added some missing styling, cleaned up param names, updated sample.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>
Merge pull request #1574 from enyojs/CMB-593-aarontam

CMB-593: Create ProgressButton