Fix ENYO-599 by avoiding changing index when removing last panel.  Also, update LERP code to handle removing an item and some minor jshint-related cleanup.
Fix ENYO-599 by avoiding changing index when removing last panel.  Also, update LERP code to handle removing an item and some minor jshint-related cleanup.

Reviewed-By: 38b4dec1f5b27072a1951c7ab42aca09271a6d55@palm.com)

enyojs/layout