Reworked panel collapse/expand animation to use pure CSS instead of javascript measurements and style animator.
Enyo-DCO-1.1-Signed-off-by: Blake Stephens <blake.stephens@lge.com>
Merge pull request #1331 from enyojs/BHV-9066-blakestephens

BHV-9066: Reworked panel collapse/expand animation to use pure CSS

Fantastic!

Reviewed-By: Cole Davis (cole.davis@lge.com)