refactor enyo.Panels for better functional decomposition
refactor enyo.Panels for better functional decomposition

Unable to extend enyo.Panels in moonstone for the desired event and panel
communication so we've refactored things a bit to allow for better
extensibility.

Issue: ENYO-719
Enyo-DCO-1.1-Signed-off-by: Ryan Duffy (ryan.duffy@lge.com)

enyojs/layout