BHV-11591 Fix JSHing defects

Enyo-DCO-1.1-Signed-off-by: David Um david.um@lge.com
BHV-11591 Preserve the first index of removing models before it is actually removed.
Getting index in VerticalDelegate.js is too late. When you try it, it is already removed from collection.
So, you will always have '-1' as a return value of indexOf()

Enyo-DCO-1.1-Signed-off-by: David Um david.um@lge.com
BHV-11591 Use pre calculated index.
For keeping consistency with modelsRemoved() and reduce O(n) execution,
use index which calculated from DataRepeater.js

Enyo-DCO-1.1-Signed-off-by: David Um david.um@lge.com
Merge pull request #797 from enyojs/BHV-11591-davidum

Bhv 11591 Prevent unnecessary refresh() to increase performance

Looks good!

Reviewed-by: Aaron Tam (aaron.tam@lge.com)