cleanup, updates and rewrites

Enyo-DCO-1.1-Signed-off-by: Cole Davis <cole.davis@lge.com>
appease jshint

Enyo-DCO-1.1-Signed-off-by: Cole Davis <cole.davis@lge.com>
add comments to introduce the needsRender element of the renderReusingNode path

Enyo-DCO-1.1-Signed-off-by: Cole Davis <cole.davis@lge.com>
remove unnecessary code

Enyo-DCO-1.1-Signed-off-by: Cole Davis <cole.davis@lge.com>
don't handle scroll events when the work for layout has already been done

Enyo-DCO-1.1-Signed-off-by: Cole Davis <cole.davis@lge.com>
remove unnecessary overhead caused by looking of size when we already know it

Enyo-DCO-1.1-Signed-off-by: Cole Davis <cole.davis@lge.com>
Merge pull request #357 from enyojs/data-list

Reviewed-By: Ben Combee (ben.combee@lge.com)
Comment cleanup. Enyo-DCO-1.1-Signed-Off-By: Jim Tang (jim.tang@lge.com)